Ittsuu Yaku: A Full 1-Through-9 Run in One Suit
Sep 22, 2026 · 4 min read
Ittsuu ("pure straight") forms when your hand contains three specific sequences in ONE suit: 1-2-3, 4-5-6, and 7-8-9. It's worth 2 han closed, 1 han open.
Why Ittsuu Feels Hard
Unlike other sequence yaku that are flexible about which numbers you use, Ittsuu needs exactly those three specific runs -- so you need to deliberately steer your hand there fairly early, rather than just following whatever tiles come.
Combos That Fit
Since it needs one suit to be fairly dominant, Ittsuu often shows up alongside Honitsu or Chinitsu. If your hand is closed, that's a realistic path to a very high-value hand.
An example Ittsuu hand -- a full 1-through-9 run in Bamboo (three sequences), plus one free set and pair.
The remaining set and pair outside the Ittsuu shape can be anything -- what matters is that those three sequences stay intact and in the same suit.
Check out a more flexible sequence yaku.
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