Yaku guides · 5 / 17
Toitoi: four triplets and a pair
Toitoi is the all-triplets yaku: 2 han for four triplets or kans and a pair, whether the hand is open or closed.
The principle
Toitoi (対々和) replaces every sequence with a triplet or kan. The completed structure contains four triplet or kan groups and a pair. The yaku is worth 2 han with no closed-hand requirement, so pon and daiminkan can be used to accelerate it.
Rule and example
The groups do not need to be yakuhai. Four triplets of ordinary number tiles are enough. Yakuhai, dora, and other yaku add value separately, but toitoi already exists whenever the complete structure contains no sequences.
What changes
Toitoi often combines with sanankou, honroutou, or several yakuhai. An ankan counts as a concealed kan, while pon and daiminkan remain open. That distinction does not change toitoi, but it does affect sanankou and possible suuankou.
Mistake to avoid
Calling every available pair makes the plan easy to read and removes defensive tiles. Before pressing pon, ask whether the call truly lowers shanten, whether enough value remains, and which dangerous tile will have to leave the hand next.
Rules references
- Tenhou rulesReference profile used for game mechanics and scoring.
- WRC Rules 2025International rules compared whenever their options differ from Tenhou.