The Sextuplets

The Sextuplets (六つ子 Mutsugo), created by Fujio Akatsuka, are the initial lead characters of the seriesOsomatsu-kun and a notable part of Akatsuka's Star System.

As their name suggests, they are a group of six identical siblings, and all brothers with their names patterned after "matsu" (pine tree). Though they may have slight differences when it comes to their personalities, they are often depicted as a unit or otherwise indistinguishable.

Overview[]

Fujio Akatsuka was given an order by Weekly Shonen Sunday to come up with a short-term gag serial that would run 4 weeks. He initially wondered about making a comedy about twin protagonists, but his wife Tomoko had pointed out that twins would be too expected. He then decided that it would be based off the title of the 1950 American film "Cheaper by the Dozen", and feature a group of twelve children as to make the gag situation more interesting. As merely twelve children alone wouldn't be a selling point, he figured "It would be funny if they had the same face".

However, Akatsuka and his editor found there would be too much difficulty with fitting twelve children into panels and that it would be too much work to have that many main characters. Akatsuka instead decided that he would cut the number in half, resulting in sextuplets. The fast popularity of "Osomatsu-kun" lead to Shonen Sunday extending it past its four chapters, and it ran in the magazine for seven years.

But as the manga developed more over the years and more cast members were added, the phenomena of "eating the main role" happened and Iyami and Chibita in particular wound up more developed and focused on through stories than the sextuplets. In some chapters, the brothers would be relegated to small supporting roles or even absent entirely; this is most pronounced in the 1972-1973 revival in Weekly Shonen King, where Iyami became the protagonist and the sextuplets either appeared only to react to his exploits or would appear in opening illustrations making statements such as "Sorry, this is the only part of the story we'll be in!" (or Osomatsu arguing with Iyami about panel-time).

The final revival of the manga in Comic BomBom and TV Magazine returned some focus to the sextuplets as the protagonists, though their supporting cast still stood out more as it had long been decided to downplay any individual differences of the brothers that may have existed at the start.

In an early installment of the manga, the surname of the family was Yamano (山野) but consistently became Matsuno (松野) and was set as such. The boys were also sometimes said to be 12 year olds, but their default age became 10.

Members[]

For any individual information on each sextuplet, please see their own pages:

Order of Brothers[]

Fujio Akatsuka never directly stated the birth order of the brothers, and the order they were listed in would not always be consistent through illustrations and media, although Osomatsu's leader role and the series being named after him leads to the implication of him being eldest. The 1988 anime adaptation and subsequent official works solidified this role for him, with him outright being referred to as the oldest brother.

One most common role-call order in the manga by Matsuyo is known to be Osomatsu, Ichimatsu, Karamatsu, Choromatsu, Todomatsu, Jyushimatsu, and is also heard recited in the 1988 anime. The older versions of the Koredeiinoda website from 2002-2008 used a tweaked version of this for their role-call, switching Jyushimatsu and Todomatsu's placements so Todomatsu would fall last and be referred to as the youngest.

This order can also be seen in the Takeshobo reprints of the manga, including their "Completely Osomatsu-kun" anthology which uses the revised positions for the last two brothers. There were also points within the manga where Todomatsu was placed as the last brother in some activities involving the order (or the first brother if working backwards), leading to question if the original listing had an oversight to begin with.

Readers may also note that it makes more sense to have Jyushimatsu fall 5th and Todomatsu be last in order to match up to Ichimatsu and Karamatsu's placements, as they are often separated off into duos with the other two as Osomatsu and Choromatsu (1st and 4th) would be. However, the first instance of duos teaming up in the manga and some other instances like "Sextuplets vs. the Great Gang of Japan" will instead have Ichimatsu and Todomatsu split off, along with Karamatsu and Jyushimatsu.

The earliest indication of the current accepted birth order (Osomatsu, Karamatsu, etc.) can be heard in the 1988 Pierrot anime adaptation's ending theme Osomatsu Ondo, other than Jyushimatsu falling last ("Even if Todomatsu drew eyebrows on Jyushimatsu's face..."). Fujio Pro employees have also stated the recent variation on this to be the right order, even though a statement on a Fuji TV program about the success of Osomatsu-san provided a contradictory statement that there was no set order and that Osomatsu "might not" be eldest.

After Akatsuka's death in 2008, the newly-established Fujio Pro corporate website and Koredeiinoda officially cemented Todomatsu's place as the youngest, and added the phrase "todo no tsumari" ("after all"/"to summarize") in descriptions of the character in the updated profiles, as a pun on him being the end of the line of the group. The corporate website and the pachinko game CR Osomatsu-kun also ran with the current order of the brothers, although the game profiles did not identify their exact placements.

On the Koredeiinoda site itself, only Todomatsu and Osomatsu's placements are confirmed while the other four boys are described as "one of the sextuplets" and that Ichimatsu is not the eldest even if he has "ichi" (1) in his name.

Theme Colors[]

The sextuplets being color-coded is more commonly associated with Osomatsu-san due to the reliance on using such theme colors as part of the identification of each brother. These are the colors as given in -san, and that can be seen reflected in the brothers' hair highlights and their clothing:

Osomatsu: Red
Karamatsu: Blue
Choromatsu: Green
Ichimatsu: Purple
Jyushimatsu: Yellow
Todomatsu: Pink

However, this was not the case for the times they were given colors in -kun. The earliest known instance can be seen in the original Weekly Shonen Sunday issue #27 for 1965, which has a frontispiece depicting the sextuplets in differently-colored uniform shirts (blue, teal, green, tan, and two different shades of purple) though none of them are explicitly identified.

The late 1980s Kodansha reprints with Takayoshi Minematsu's art have front covers that occasionally color-code the boys, yet not necessarily specifying their identities each time, along with the back covers depicting a line-up of colored squares with each boy's face in them.

The 1995 Takeshobo reprint covers depict CGI models of the sextuplets, with only Osomatsu wearing the regular blue outfit and the five other brothers given colors to set them apart:

Ichimatsu: Orange
Karamatsu: Red (rendered as more of a pink in the CGI)
Choromatsu: Green
Todomatsu: Yellow (his uniform coat buttons become green as a result)
Jyushimatsu: Purple

A 2016 April Fools' joke on the Osomatsu-san website adhered to the -kun era Osomatsu being blue and Karamatsu being the red brother, but switched the colors around for the other four (making Choromatsu yellow, Ichimatsu purple, Jyushimatsu green, and Todomatsu orange).

As this is not often a detail important to -kun, such an aspect is less consequential if at all in aiding in identification and the games continue to run with having all six boys dress in blue.

Naming Scheme[]

Each brother's name ends in the 松 (matsu) kanji, meaning "pine tree". Of the existing six brothers, two each have their names inspired by the same type of theme; likely playing into why Akatsuka often used those specific two in couplets.

Osomatsu and Choromatsu had their names seem to derive from their speed and competency, Osomatsu's name representing "poor" while Choromatsu representing a quick child.
Ichimatsu and Jyushimatsu's names are represented with kanji for numbers (for 1 and 14 respectively), as Akatsuka realized that many actual names derived from numbers (such as male names Ichiro, Saburo, and those in a similar fashion). Furthermore, Fujio Pro reminds readers that one shouldn't mistake Ichimatsu's name for the 市松 spelling meaning "checkered", and that Jyushimatsu can sing as well as a 十姉妹 (jyushimatsu/"ten sisters", the Japanese name for the Bengalese finch).
Karamatsu and Todomatsu were named after trees, allegedly so kids would recognize the names in class. Karamatsu is the larch tree, while Todomatsu is the abies fir. Of course, Fujio Pro opts to make further puns related to these names, with Karamatsu being described as karappo or just kara (empty) and karagenki (empty-spirited), while Todomatsu is the youngest child, todo no tsumari (after all).

In alternate settings where the brothers are living in the USA, such as Wild West-themed stories, the notation of their names is entirely in katakana to represent the names not being of Japanese origin. Each name thus ends in マツ (matsu), or マーツ with a chōonpu through it. In merchandise more catered towards younger children, the brothers' names are entirely represented in hiragana to make them easier to read, so the "matsu" ending is put as まつ.

Their early one-time surname Yamano is a common one meaning "wilderness", while Matsuno means "pine tree field". According to the backstory as decided by Akatsuka and Fujio Pro in the liner notes to a 1964 summer special, their father named all six with a pine/matsu theme due to his lack of creativity about names. The parents' own names are simply "Matsu" with some form of common name ending for men and women ("zo" and "yo").

Physical Appearance[]

As children, their height, weight, and overall hair and clothing styles are exactly the same no matter what. Due to this, it is virtually impossible to tell the six apart and even them dressing differently may not tell you who is who unless there's name-dropping involved.

These brothers are best known for wearing their hair short with an initially side-swept fringe that is later depicted as more even and bowl-cut from the front, to where they may be ridiculed for this "botchan" hair. Two cowlicks (or ahoge, "idiot hair") stick up in the back. They are often seen wearing a three-buttoned uniform coat with a white collar, usually lighter pants, and dark athletic running shoes to suit their coming and going to school. In summer seasons, they tend to wear shorts and shorter-sleeved shirts. The reason for their identical clothes, according to Matsuyo in the first chapter, is that it's cheaper and easier to buy them in bulk.

The sextuplets are initially depicted by Akatsuka with much different facial features in the first chapter; large snub noses, smaller eyes, and longer mouths, as well as freckles in the early frontispieces to chapters. They are also shorter in the first chapter, but such a design was quickly swapped out for them having cuter faces, and the boys' designs gradually evolved to the more iconic look.

Their designs were steadily re-interpreted over the run of the manga by Akatsuka and his assistants, Kenichiro Takai being the most prominent during the Shonen Sunday run and Kunio Nagatani also drawing them often for merchandising artwork. The last and current artist to draw them is Takayoshi Minematsu (current alias: Katta Yoshi) in all later and posthumous Fujio Pro illustrations and content, including new tankobon artwork either referencing their earlier designs or being in Minematsu's own usual style.

An overall art evolution can also be seen in the Pierrot anime, with the designs starting out closer to the manga; particularly seen in episodes directed by Masami Abe and Motosuke Takahashi. But after some time, no matter which animation director is involved, the sextuplets' designs gradually evolve to become more super-deformed and the end result is them being significantly shorter and chubbier than they started out. It is thought that the simplified designs may have suited the frantic comedic tone better, or that they were easier to draw and animate. It can be noted that some details like that of the boys' running shoes were also sacrificed in the process.

Adult versions of the sextuplets, including the recent incarnations in Osomatsu-san, tend to be distinguished from one another with physical differences in their designs. In -kun itself, even if the adult sextuplets' personalities may not be as clear, they can be more readily told apart if one is bald or one has a mustache. Different variations may exist depend on a given setting.

The 1988 guide "Osomatsu-kun's Burst of Laughter World-zansu" by Kodansha gives these shared measurements for them as children, based off some details from the manga as well as some further trivia to pad out their statistics:

Blood type: A
Height: 150 cm (4'11)
Weight: 46 kg (101 lbs)
Foot size: 22 cm (8.6 in)
Foot length: 60 cm (23.6 in)
Visual acuity: 2.0
Cavities: 3 (for Osomatsu)

Personality[]

The sextuplets usually act in unison and are shown to be just as greedy and mischievous as each other. They love money, food, and are charmed by cute girls their age. They can range in a more heroic to antagonistic role depending on the setting, but may sometimes just be minor details in a story or show up all too briefly.

These six can use their identical looks to their advantage in fooling others, but can also be frustrated by being mistaken for one another and show that there is disadvantage to being a group of same-faced brothers.

They are clever but stubborn, and when it comes to general education they tend to not be very bright as witnessed in some stories, failing their tests or not even knowing simple math equations. Between the six, some may also have varying athletic ability, as one can be seen tripping and falling whenever they run.

Early on, there are some personality differences that can be witnessed between the six and some materials make it a point to state that they look identical but act differently, but later descriptions and treatment of the brothers often lump them together as one and as "looking and acting the same". The personality settings shown in Shonen Sunday notes by Akatsuka vs. Fujio Pro's current settings are not always congruent with each other either; it can be said that out of them, Osomatsu has remained probably the most consistent in being described as a hooligan.

When the sextuplets are not all together, Osomatsu may act solo or they may be divided off into their duos with Osomatsu and Choromatsu being the most commonly-seen.

For details on any individual personality traits of the brothers, you may refer to their own articles above. In animated adaptations, the boys can be differentiated slightly by their voices although they often may not be name-dropped which will lead viewers to deduce who is who.

Behavior and Story Settings of Sextuplets[]

"Clean Sextuplets": The Matsunos will be portrayed as more innocent and heroic, in charge of punishing those who do wrong. Even when mischievous themselves, they are set to be in the right.
"Scummy Sextuplets": The Matsunos are the trouble from the start, committing violent and unreasonable acts against others. In such a setting, Chibita and Iyami are the heroes.
"Sextuplets Pretending to be One": To lighten on travel expenses or for some other type of deceit, the sextuplets will attempt to conceal their true nature and hide, with each of them attempting to act as the same unified person.
"Disguised Sextuplets": The sextuplets may dress up for purpose of disguise or some event.
"Inhuman Sextuplets": A setting where cartoon physics are used freely with the sextuplets. This can be seen early on with hair popping off heads as if it were a wig when in shock, but more notably used when Ichimatsu mows down Chibita with a road roller or when the sextuplets gain psychic powers in a BomBom story and use them to stretch parts of their bodies.
"Cross-dressing Sextuplets": A device that is usually limited to just Osomatsu or a few brothers, and rarely the whole group. For whatever reasons in a story, a sextuplet will be made to cross-dress as a girl.
"Period Drama Sextuplets": The sextuplets as seen in Edo-era stories, usually cast in minor townspeople roles.
"Antisocial Sextuplets": The sextuplets will be cast as yakuza or other mob/gangster-types of characters; this can also overlap with the above when they're portrayed as wicked henchmen in a period drama story.
"Garden Guard Sextuplets": The official in-story name for the sextuplets acting as ninja to defend their house, from the chapter of the same title. They are depicted wearing black cat-eared hoods.
"Western Sextuplets": The sextuplets as sheriffs or plain cowboys in Wild West-settings, usually depicted as the enemies of Iyami, Chibita, or both.
"Soldier Sextuplets": The sextuplets will be made to act as soldiers, or will already be set in such a role in WW2-era drama ("The Iyami Platoon Strikes").
"Employed Sextuplets": Compared to their older counterparts in Osomatsu-san, the Osomatsu-kun sextuplets can occasionally show motivation and ambition to work. Some settings may show them working at their parents' inn or another shop, running an amateur business with their parents to make money, or they may work at a laboratory as scientists (which is also shown with their 40-year old selves in "Osomatsu-kun after 30 years").

Relationships with Other Characters[]

Chibita[]

Totoko[]

Iyami[]

Matsuyo Matsuno (Mom)[]

Matsuzo Matsuno (Dad)[]

Dekapan[]

Hatabō[]

Dayōn[]

Family and Lookalikes[]

The sextuplets' extended family is often not shown, with the parents or children themselves mostly vaguely referring to "relatives" at times.

There is one case where a childless couple are notably shown to be distant relatives of the family living in the Kansai region, and wish to adopt one of the brothers for themselves. This ultimately backfires when neither Osomatsu or Choromatsu can put up with being separated from their family.

Another Kansai region couple appear in the BomBom run, however they don't appear to be related to the family but are simply entirely identical to Matsuyo and Matsuzo as a joke about identical strangers. They exist as a punchline to solve the mystery of how two extra but unrelated sextuplet lookalikes had come to join the boys (see "Imposters").

Imposters and Extra Brothers[]

The Shonen Sunday run was known to occasionally have an error or easter egg of an extra, seventh Matsuno slipped into panels (somewhat comparable to instances of Disney's Donald Duck mistakenly being drawn with four nephews in his comics). This sort of error also occurs more than once in the 1966 anime adaptation by Children's Corner and Studio Zero, and even in the Studio Pierrot anime.

However, there are instances including the fourth chapter where there being an extra brother is entirely intentional and part of an imposter plot. These are the various situations where the number of Matsunos may be increased, and who is responsible for doing so:

Ponta (7): A tanuki appearing in the fourth chapter, who transforms into Osomatsu as revenge for being picked on by him. He and his father decide to make trouble for the family and get driven away, but then return for revenge in the fifth chapter (marking an early rare case of continuity and follow-ups to a story).
Sextuplet Dolls (12): Life-size dolls of the sextuplets created by a scientist. They appear to be entirely inanimate, but are later shown to be highly destructive and chaotic when activated. The 1966 anime leaves the later detail out, and in the 1988 anime, a looser adaptation of the story involves Iyami creating six drone-minded clones of the brothers with his copier machine.
"Mechamatsu" (7): A robotic duplicate of Osomatsu created by Iyami to cause trouble, in revenge for Osomatsu ruining a scam invention of his.
Gonbeda and Jinbeda (8): Two alien invaders that came to collect data on Earth. Osomatsu and Choromatsu are abducted by their group, and a large taiyaki mold is used to transform the aliens into duplicates of the boys. But these disguises are not entirely stable, and can be undone and deformed when they stretch or when they get intoxicated. When Osomatsu and Choromatsu return home, the other boys become frightened by there being extras and Matsuzo uses a math problem to weed out the aliens for being too intelligent.
"Osomatsu and Choromatsu twins" (8): A mysterious pair of boys that suddenly appeared at the Matsuno house one day, hiding among the sons. They claim that their names are Osomatsu and Choromatsu, but speak in a Kansai dialect. They are later revealed to be the sons of the Matsuno-like couple. The story can be seen as a loose remake (in terms of the "8" gag) of the above alien scenario, down to Matsuzo attempting to weed out the fakes.
"Usomatsu" (7): A runaway fugitive that takes on the appearance of the sextuplets, due to a special transformation machine created by Dekapan after the fugitive pays him off to do so. He is later discovered and apprehended when his money turns out to be counterfeit, and is referred to as "Usomatsu" (Liematsu/Fakematsu) by the Police Officer with the Connected Eyes. The "Usomatsu" name is also used as a gag to ID the Kansai Osomatsu by in the frontispiece to the story about the twins.
Minematsu, Basuomatsu, Uematsu, Chumonmatsu, Henjimatsu, and an unnamed brother (12): Six extra children created as an ending gag in the "Mutsumatsu" story; Mutsumatsu steps on Dekapan's fusion machine and it explodes, causing him to be forcibly split apart not only back into his components but also an extra six. Basuomatsu's name is a pun on "Wait for the bus!" (バスを待つ basu o matsu), Chumonmatsu's name is a pun on "Wait for an order!" (注文待つ chumon matsu), and Henjimatsu's name is a pun on "Wait for an answer!" (返事待つ henji matsu). Minematsu is named after Takayoshi Minematsu, as he had been drawing the manga at this point, and the boy can be seen drawing on a manuscript.

History[]

Appearances in other works[]

See also: Akatsuka's Star System

Many times, it is easier for Akatsuka and assistants to simply represent the group with a few brothers. However, there are instances where all six will be seen yet usually not distinguished.

Akko-chan's Got a Secret!
Songo-kun
Gyahaha, the Three Musketeers!
Extraordinary Ataro
The Genius Bakabon (Five depicted as illustrations in a manga titled "Usomatsu-kun")
The Monkey's Foolish Guardman (Four of the brothers)
There's no Wonderful Business like that of a Gag!
Nyarome's World Expo Surprise Surprise Surprise Guide
Let's La Gon (seven brothers' faces appear in a letter/intro)
Unkor Wat
Wanpei and Mo-chan (Five brothers visible in a strip)
Nyarome's Fun Biology Classroom
Nyarome's Fun Exploration of the Body's Mysteries (all six in two cameos, then four in their group final cameo)
Nyarome's Fun Sexual Education Classroom (all six in chapter 9, other smaller numbers of brothers at earlier points in the book)
Nyarome's Big Blood Type Studies
What Will Fujio Akatsuka Do!? (All six in opening spread)
Japan Laughter Story (Three brothers shown as policemen)
Reading Dai-sensei (Three brothers shown in a sport competition)
Hana-chan Sleeps (Two unidentified brothers, as adults in the seventh chapter)
Sheeh! Comeback
Collapse of the Sheeh! Religion

Appearances in Animation[]

Osomatsu-kun (1966)[]

Furious Ataro (1969)[]

The six first appear as a unit in the Edo prologue sequence to episode 48; five brothers are depicted in chonmage haircuts and traditional clothing, but an odd brother out (likely Osomatsu) has his usual bowlcut and a different outfit.

They then make a notable appearance in episode 74 as plane passengers of a hijacked flight to Hong Kong. They mostly speak in unison, though some boys get some words on their own.

We are Manga-ka: The Tokiwa-so Story[]

The six briefly appear outside of Tokiwa-so in the winter, engaged in a game of battledore.

Hitachi Television City: Nyarome's Fun Mathematics Classroom[]

The sextuplets are featured among the Akatsuka Stars present in the segments, including the opening theme "I'm Not Scared of Mathematics" which is sung by a number of characters.

Osomatsu-kun (1988)[]

Osomatsu-san[]

For detailed information on this derivative work, see the Osomatsu-kun and Osomatsu-san wiki

Portrayals[]

Voice Acting[]

1965 Sonosheet "The Medicine Strategy of Chibita"- Minori Matsushima (Osomatsu), Keiko Yamamoto, Tomoko Sayama, Tomono Mitamura (Other sextuplets, unspecified in credits)
1965 Sonosheet "We'll Do Anything In 6 Rounds!"- Minori Matsushima (Osomatsu), Makiko Ito, Hiromi Yamagishi, Kazuko Yoshikawa (Other sextuplets, unspecified in credits)
Osomatsu-kun (1966)- Midori Kato (Osomatsu), Keiko Yamamoto (Karamatsu, Choromatsu), Haruko Kitahama (Ichimatsu, Todomatsu), Mie Azuma (Jyushimatsu)
Furious Ataro (1969)- Masako Nozawa (five brothers in episode 48), Sachiko Chijimatsu (Osomatsu, episode 48)
We are Manga-ka: The Tokiwa-so Story (1981)- Keiko Yamamoto and Kazuko Sugiyama
Hitachi Television City: Nyarome's Fun Mathematics Classroom- Information currently unknown
Osomatsu-kun (1988)- Yo Inoue (Osomatsu), Mari Mashiba (Karamatsu), Rica Matsumoto (Choromatsu), Mari Yokoo (Ichimatsu), Naoko Matsui (Jyushimatsu), Megumi Hayashibara (Todomatsu)
CR Osomatsu-kun- Yui Shoji (All brothers)
That's How Things Should Be!! The Fujio Akatsuka Movie- Maki Horikita, Ayumi Ishida, Tae Kimura
Osomatsu-san- Takahiro Sakurai (Osomatsu), Yuuichi Nakamura (Karamatsu), Hiroshi Kamiya (Choromatsu), Jun Fukuyama (Ichimatsu), Daisuke Ono (Jyushimatsu), Miyu Irino (Todomatsu)
Pachislot Osomatsu-kun- Mari Mashiba (Karamatsu), Naoko Matsui (Jyushimatsu). Other actresses are currently unconfirmed due to lack of printed credits for the game.

There are occasionally cases of understudying in both the 1966 and 1988 shows when it comes to the voices of particular sextuplets. Mari Yokoo was also not the initial actress for Ichimatsu in the 1988 series, but came to be associated as his voice in the middle term of the show.

Live Action[]

Yosuke Nakajima (Osomatsu), Hideyuki Nakayama (Karamatsu), Daisuke Matsuno (Todomatsu), Hiroshi Isono (Choromatsu), and Masami Yamaguchi (Jyushimatsu) are among the young men that have been said to have portrayed the sextuplets in the 1985 Monday Dramaland special where they are instead adults working at their father's restaurant.

Foreign Names[]

Note: The order of names given in these dubs is based from the original "Osomatsu, Ichimatsu, Karamatsu, Choromatsu, Todomatsu, Jyushimatsu" setting, as it is Matsuyo's role-call in the 1988 show.

Thus, "Jisong" in the case of the Cantonese dub would be referring to Ichimatsu and not Karamatsu.

Language	Name	Origin
Cantonese (Hong Kong)	Dasong, Jisong, Sansong, Sisong, Wusong, Liusong	"Big Pine", "Second Pine", "Third Pine", "Fourth Pine", "Fifth Pine", "Sixth Pine".
Mandarin (Taiwan)	Xiaosong, others' names unknown	"Small Pine".
Korean	Gidung, Sundung, Cheondung, Heodung, Makdung, Bindung	"Pillar", "Gentle", "Thunder", "Hurdle", "Page", "Hollow".

Gallery[]

Trivia[]

To save on having to draw all of the brothers, Akatsuka and assistants attempted to employ a "copy and paste" method of drawing and clipping out facial expressions for them, which he would photocopy and paste onto their bodies on the manuscript paper. But as even this method became too time-consuming and troubling, it was discontinued with after a while. This can often be spotted when the sextuplets' heads appear to have thicker lineart than their bodies. The practice was brought back in the 1980s run of the manga, although now entire poses of a sextuplet would be copy and pasted as well.