# Chiitoitsu (七対子) — Riichi Mahjong Yaku

> The hand consists of seven different pairs.

**Source:** https://www.mahjongmaster.co/learn/riichi/yaku/chiitoitsu/
**Author:** Kenji Tanaka (https://www.mahjongmaster.co/about/kenji-tanaka/)
**Publisher:** Mahjong Master (https://www.mahjongmaster.co)
**Published:** 2026-02-14
**Updated:** 2026-03-10
**Japanese:** 七対子 (Chiitoitsu)
**Han value:** 2 han
**Category:** special
**Difficulty:** intermediate
**Frequency:** common
**Closed only:** yes

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## Overview

Chiitoitsu, seven pairs, is a special closed yaku worth 2 han that breaks the usual four-melds-and-a-pair structure: it is made of seven distinct pairs, each a different tile. It must be concealed, since pairs cannot be called, and it is always scored at a fixed 25 fu, giving it a distinctive payout. Most rule sets require the seven pairs to be genuinely different tiles, so four of a kind cannot count as two pairs. Chiitoitsu always finishes on a tanki (single-tile) wait completing the final pair, and it combines well with tanyao, honitsu, and especially riichi, where its tanki wait can be aimed at a safe or likely tile. It is a useful escape route when a hand holds many pairs but few good sequence or triplet shapes. Skilled players weigh chiitoitsu against a standard hand based on which reaches a stronger wait faster.

## Conditions

- The hand must consist of exactly seven pairs (14 tiles total, forming 7 pairs of 2 identical tiles each)
- All seven pairs must be different; four of the same tile does not count as two pairs for chiitoitsu
- The hand must be fully concealed (closed only); you cannot call pon, chi, or kan
- Always scored as 25 fu with a flat 2 han, regardless of tile composition
- Cannot combine with iipeiko or ryanpeikou since those require sequence interpretation

## Strategy Tips

- When your starting hand has four or five pairs, chiitoitsu becomes a realistic target. Count your pairs at the start and decide early whether to pursue this path.
- Chiitoitsu tenpai is always a single tile wait (tanki), which can be hard to read for opponents. Use this to your advantage by waiting on a tile that appears safe or has few discards.
- This hand pairs naturally with tanyao (all simples pairs), honitsu (one suit plus honors), or honroutou (all terminals and honors) for significant bonus han.

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*This content is from [Mahjong Master](https://www.mahjongmaster.co), a free educational reference for riichi (Japanese) and American (NMJL) mahjong. When citing this page, please link to https://www.mahjongmaster.co/learn/riichi/yaku/chiitoitsu/.*