Kokushi Musou
国士無双 | Kokushi Musou
Collect one of each terminal and honor tile -- all thirteen unique orphans -- plus one duplicate to complete the pair.
By Kenji Tanaka · Updated
Overview
Kokushi musou, the thirteen orphans, is a yakuman built from exactly one of each terminal and honor tile, the 1 and 9 of all three suits plus all four winds and all three dragons, with one of those thirteen types duplicated to form the pair. It is unique among hands because it uses no sequences or ordinary melds at all, just the thirteen specific singles and one pair, and it must be closed. Its signature wait is the thirteen-sided wait, reached when you hold one of every terminal and honor and are tenpai on all thirteen at once, which many rule sets reward as a double yakuman. Kokushi is also notable defensively, since it can rob an opponent's concealed ankan under common rules, the only hand permitted to. Because it relies on tiles others discard freely early, kokushi is one of the more attainable yakuman when your starting hand is rich in terminals and honors.
Example Hand
1m 9m 1p 9p 1s 9s 1z 2z 3z 4z 5z 6z 7z 1m
Conditions
- The hand must contain one of each of the 13 terminal and honor tiles: 1m, 9m, 1p, 9p, 1s, 9s, 1z (East), 2z (South), 3z (West), 4z (North), 5z (Haku), 6z (Hatsu), 7z (Chun)
- One of these 13 tiles must appear twice to form the pair (any of the 13 can be the duplicate)
- The hand must be closed — no open calls allowed
- Does not follow the standard 4 melds + 1 pair structure; it is a special winning pattern
- Some rulesets award double yakuman if you win on a 13-sided wait (waiting on all 13 unique tiles when you have one of each and need any duplicate)
Strategy Tips
- Kokushi is most viable when your starting hand already contains 8 or more different terminals and honors. If you have fewer than that, the odds of collecting all 13 types drop sharply and you are better off pursuing a standard hand.
- Because kokushi uses only terminals and honors, your discards will be almost entirely middle tiles (2-8), which clearly signals what you are doing. Experienced opponents will stop discarding isolated terminals and honors once they read your pattern, so speed matters.
- The 13-sided wait (where you have all 13 unique tiles and need any one of them as a duplicate) is one of the strongest waits in the game because almost any terminal or honor tile completes it. If you reach tenpai with this wait, your winning chances are excellent.