Yaku guides · 4 / 17
Chiitoitsu: seven pairs
Chiitoitsu is a closed hand made from seven distinct pairs, worth 2 han with a fixed total of 25 fu.
The principle
Chiitoitsu (七対子) is one of the two winning structures that do not use four groups and a pair. It requires exactly seven distinct pairs and a fully closed hand. The yaku is worth 2 han and always scores 25 fu, without adding the usual fu for ron or the pair.
Rule and example
Four identical copies do not make two distinct pairs. A winning chiitoitsu needs exactly two copies of seven different tile types. A fourteen-tile shape containing 1111m therefore cannot be completed as chiitoitsu.
What changes
Chiitoitsu combines well with riichi, menzen tsumo, tanyao, honitsu, chinitsu, or honroutou. It does not stack with iipeikou or ryanpeikou because those yaku use the standard sequence interpretation. When several readings seem possible, only combinations compatible with the winning structure count.
Mistake to avoid
While building the hand, isolated honors and already visible tiles change the quality of each pair candidate. Six pairs do not promise a quick tenpai when the final useful tile is nearly dead. Count the actual ukeire rather than only the pairs in front of you.
Rules references
- Tenhou rulesReference profile used for game mechanics and scoring.
- WRC Rules 2025International rules compared whenever their options differ from Tenhou.