Ryanpeikou (Two Pairs of Identical Sequences)
A closed hand containing two separate pairs of identical sequences (two iipeiko shapes). 3 han, closed-only. Mathematically a chiitoitsu shape, so most rulesets do not let a hand score iipeiko twice instead — ryanpeikou simply replaces the would-be 2 han stack.
Read the full explainer →Example hand
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Open in shanten calculator →Related yaku
Honitsu (Half Flush)
3 HanA hand containing only one numbered suit plus honor tiles. 3 han closed, 2 han open. The workhorse high-value open yaku — combined with a yakuhai triplet it routinely clears mangan even after multiple calls.
Junchan (Pure Outside Hand)
3 HanLike chanta but contains no honors — every meld and the pair contains a terminal (1 or 9). 3 han closed, 2 han open. Higher value than chanta but brittle: a single honor tile anywhere in the shape downgrades the hand to chanta.
Double Riichi
2 HanRiichi declared on the very first uninterrupted turn — no calls have happened yet. Closed-only. 2 han instead of riichi's normal 1, with the ippatsu window starting the same turn so the bonus-han chance is the highest of any riichi variant.