Sanankou
Last updated: 2026-08-18Sanankou means three concealed triplets (including concealed quads) — fixed 2 han. The triplet completed by ron does not count as concealed. See Riichi Mahjong Yaku Guide and Toitoi.
Requirements
- Three triplets/quads are concealed (drawn or concealed quad, not open)
- On ron: the triplet completed by the winning tile is treated as open — does not count
- 2 han
Two concealed triplets alone is not sanankou. Suuankou is yakuman — not a separate article in this batch.
Valid example
Three concealed triplets (m111, p222, s333) + man 456 sequence + white pair. Ron on white completes — sanankou applies.
Invalid or confusing
Only two concealed triplets — ron on 6 man gives no sanankou; tanyao may still apply.
Stacking and open hands
Often stacks with Toitoi (closed ron on fourth triplet is typical). Melding reduces concealed triplets.
Scoring
Each concealed triplet adds fu. Sanankou + toitoi shapes have high fu. See Fu Calculation Basics.