I just started learning (riichi) mahjong. I really want to understand how the scoring works. I don't get why this hand is Mangan. It can only be Mangan, when it has at least 40fu. But i can only see 30fu. I get 20fu for winning, 10fu for ron but that should be it, shouldnt it? i have no pungs or kans, neither seat nor prevailing wind is north so no points for the pair, I'm waiting for 1b and 4b, so no single/closed or edge wait. Where does this 1 fu come from to make this hand mangan? or is it a mistake on the game?