Iipeikou (一盃口)
Two identical chows in the same suit. Closed hands only.
How Iipeikou (一盃口) works
Two identical sequences — the same three tiles in the same suit appearing twice, such as two runs of 2-3-4 sou.
Iipeikou is formed when two of the hand's four sets are exact duplicates in suit and rank. It can only be scored with a fully concealed hand, since calling a chow breaks the requirement that both runs be self-formed. It combines freely with pinfu, tanyao, and the flushes; doubling it into two separate identical pairs of runs instead becomes ryanpeikou.
- •Closed hand only; an open meld voids it.
- •Both sequences must match exactly in suit and starting tile — different suits do not count.
- •If the hand instead holds two distinct duplicated-run pairs it is scored as ryanpeikou, not as iipeikou twice.
Iipeikou (一盃口) — FAQ
Can iipeikou appear twice in one hand?
No. Two separate identical-sequence pairs are scored as the higher ryanpeikou yaku, never as iipeikou counted two times.
Does iipeikou work with a flush hand?
Yes. Since identical runs sit within a single suit, it stacks comfortably with honitsu or chinitsu as long as the hand stays closed.