Double Riichi
Riichi 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.
Example hand
234m234p678p234s99m
Open in shanten calculator →Related yaku
Chiitoitsu (Seven Pairs)
2 HanA closed hand of exactly seven distinct pairs. The seven pairs must all be different tiles — duplicates of the same pair count as one. Scores a flat 25 fu and pairs well with honor-heavy or mixed-suit hands that resist forming triplets.
Sanshoku Doujun (Three-Color Straight)
2 HanThe same numerical sequence in all three numbered suits (e.g., 234m / 234p / 234s). 2 han closed, 1 han open. Often paired with pinfu or tanyao, and structurally exclusive with ittsu — pick one or the other based on whether your early draws cluster vertically or spread horizontally.
Ittsu (Pure Straight)
2 HanSequences 1-2-3, 4-5-6 and 7-8-9 all in a single suit. 2 han closed, 1 han open. The same-suit cousin to sanshoku-doujun — vertical inside one suit versus sanshoku's horizontal three-suit spread, and the two cannot coexist.