Yaku guides · 12 / 17
Honitsu: one suit with honors
Honitsu, the half flush, is one numbered suit plus honors: 3 han closed, 2 han open. When to open it and how to read it in the kawa.
Honitsu rule and value
Honitsu (混一色), often called half flush in English, combines exactly one numbered suit, manzu, pinzu, or souzu, with at least one honor. No tile from either of the other numbered suits may remain in the winning hand. The yaku is worth 3 han closed and 2 han after an open chi, pon, or kan.
Honitsu or chinitsu?
The honor is what separates honitsu from chinitsu. If the last honor leaves and only one numbered suit remains, the hand becomes chinitsu and gains value. Keeping an isolated honor solely to preserve the label can still slow the hand. Compare that possible upgrade with the ukeire actually lost.
When to open a honitsu hand
Honitsu supports many structures. It can accompany yakuhai, ittsuu, chiitoitsu, toitoi, or suitable sequence yaku. Opening costs one han, but a call that secures a value group or lowers shanten can still pay. Before the first call, identify the final yaku and the minimum score you will retain.
Reading a flush in the kawa
Defense against a flush begins in the kawa. Repeated early discards from two suits, followed by calls in the third, strengthen the honitsu read. They do not prove the exact wait. Tiles from the kept suit and unseen honors become more concerning as the hand moves closer to completion.
Rules references
- Tenhou rulesReference profile used for game mechanics and scoring.
- WRC Rules 2025International rules compared whenever their options differ from Tenhou.