Iipeikou
一盃口 | iipeikou
Your closed hand contains two completely identical sequences in the same suit.
By Kenji Tanaka · Updated
Overview
Iipeikou, one set of identical sequences, is a 1-han yaku, available only on a closed hand, formed when you hold two identical sequences, the same three numbers in the same suit, such as two runs of 2-3-4 in bamboo. Because calling a tile to make a sequence would open the hand, iipeikou disappears the moment you chii, which is why it is strictly a concealed-hand yaku. It combines smoothly with pinfu, tanyao, and riichi, since all favor sequence-rich closed hands, and a hand can even contain two separate pairs of identical sequences, which upgrades it to the higher 3-han ryanpeikou. Iipeikou adds modest value but comes naturally out of efficient closed hands that draw doubled-up runs, so it often appears almost by accident alongside other yaku. Recognizing when your shape has quietly formed a second identical sequence is an easy way to add a han.
Example Hand
3m 3m 4m 4m 5m 5m 2p 3p 4p 7s 8s 9s 6p 6p
Conditions
- Your hand must contain two identical sequences — same numbers, same suit (for example, two sets of 3-4-5 in bamboo)
- Your hand must be completely closed (no open calls)
- The two sequences must be in the same suit and have the same numbers
- Having two such pairs of identical sequences would instead be ryanpeikou (2 han, a separate yaku)
Strategy Tips
- Iipeikou often develops naturally when you draw multiple copies of consecutive tiles in the same suit. If you notice you’re holding pairs like 3-3-4-4 in a suit, keep an eye out for the tiles that would complete a double sequence.
- Since iipeikou requires a closed hand, resist the temptation to call chi on tiles that would break the pattern. The extra han from iipeikou is usually worth keeping your hand closed.
- This yaku combines well with pinfu and tanyao. A closed hand with two identical sequences made of middle tiles can easily hit pinfu + tanyao + iipeikou for 3 han, which is a solid score.