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Episode 21A Infobox Photo

First aired on

February 29, 2016

Japanese title


Romaji title


Previous episode

Episode 20: Teach Me, Hatabo, School Matsu, & Iyami's School

Next episode

Episode 21B: God Matsu

Episode 21A: Mahjong is the first half of the twenty first episode of Osomastu-san.



In a windy and stormy night, the Sextuplets sit around the table and start playing Mahjong. Initially, Osomatsu, Choromatsu, Jyushimatsu and Todomatsu are in play, while Karamatsu and Ichimatsu sit back and watch.

In the first round, Osomatsu quickly establishes a Richi, causing everyone else (including Jyushimatsu) conduct complex calculations. The round ends without anyone completing his hand, much to everyone's relief, but as Osomatsu reveals his hand (as required by the rule), they find out that Osomatsu's hand is too cheap to worth serious defense.

Karamatsu starts to describe the playing style of each brother (including himself). Both their strengths and weaknesses are mentioned:

  • Osomatsu: An aggressive player, he sticks to his choice of tile after deciding which one would win him the game. However, this makes him easily giving out others' winning tile, causing him to lose all the point bars before the game round could end. (Ichimatsu replaces him after he loses in this manner)
  • Todomatsu: He's also aggressive but almost all his moves are calculated. Similar to Osomatsu however, his playing style easily lets other players bring their hands ready for completion, often leaving Todomatsu himself in serious dilemma.
  • Choromatsu: He's a master of defense mahjong and his skills are regarded as one of the strongest. However he's unable to hide his feelings when he makes a Richi, meaning that others already know exactly what tile he would want.
  • Jyushimatsu: A player relying on sheer luck, he has a tendency to complete small hands frequently in order to win big. However, his carefree style also easily lands himself into mistakes. For example, Ichimatsu finds out that he has made a "short hand" (fewer tiles than required) when he declares winning.
  • Ichimatsu: He brings his dark aura into play and nobody can anticipate what is in his mind. However, Ichimatsu is a typical bad player, both in terms of skills and temper, and he often overturns the table in rage when he loses. (Karamatsu replaces him after a loss)
  • Karamatsu: A perfectionist, he can build good hands quickly but won't declare win unless he succeeds in building a maximum-point hand. This allows others to complete their hands in time.

Things Get Serious

After Karamatsu finishes his narration, Osomatsu declares that he's "bored" and asks other for a more serious play, namely no one needs to leave play because of loss.

In a long streak of luck, Osomatsu keeping being the starter of the game and manages to win 50042 times. This causes the other brothers to engage in crazy behaviour:

  1. Todomatsu, fearful of another win by Osomatsu, rejoices after he discards a valueless tile.
  2. Choromatsu follows Todomatsu by doing the same – with a twist that he draws on an empty tile to cheat.
  3. Karamatsu mysteriously manages to present a hand consisting of 14 identical tiles (usually there are only 4 copies of any tile in a standard Mahjong set), declaring it as a "Jyushimatsu" (Specifically, Karamatsu is holding 14 "Bamboo 1" tiles, each of which bears the symbol of the Matsuno family).
  4. Jyushimatsu randomly picks 4 hand combinations before stripping himself in front of the remaining tile, calling it a "naked single".
  5. Ichimatsu uses the mahjong tiles to assemble a model of Hijirisawa Shonosuke.

The other brothers then strips themselves and dance around the table. Enraged, Osomatsu declares that he would never play mahjong with his brothers again.