Tsumo!In short, it's a yaku you don't get if you agari via "ron" or if you've done any fuuro other than ankan.Ton second round, Nancha, in tenpai as shown belowShimocha discards 4-wan on turn 7In the example below, the other players' turn 7 discards and your turn 8 draw are where you could potentially get ippatsu.However, if during this time there is any fuuro from another player, you can no longer get ippatsu!Kamicha calls pon on shimocha's 4-wanAs of the pon, the possibility of ippatsu is gonePon!You've performed fuuro so you don't get menzenchin tsumohouYour only fuuro is ankan so you get menzenchin tsumohouAlthough in some rules, the chance for ippatsu extends up through the discard of the player whose fuuro it was.1 & 2 are ryanmen waits and the jyantou meets the condition, so they count
3 is a kanchan wait, 4 is nobetan, so they're no good for pinfu
5's jyantou is bakaze, 6's is jikaze, and 7's is sangenpai, so obviously they're no good for pinfuAfter declaring riichi, if you agari on one of the other players' discards in that go-around or on your next draw, you get ippatsu, a yaku worth one han.If you are menzen, regardless of riichi or not, and you win on the tile you drew, you get "menzenchin tsumohou", a yaku worth 1 han.
It is very often called by the abbreviation "tsumo".ExampleWaitThe next yaku I'll introduce is the relatively easy to get "pinfu".
It's worth 1 han.
Pinfu requires all of your mentsu to be shuntsu, as well as the following conditions:
・Your wait is ryanmen
・Your jyantou is not "bakazepai", "jikazehai", or "sangenpai"
Naturally, this also means your jyantou cannot be renfonpai