Million Shanten Sadame da!!

Sadameda Souta, a college student who is considered the unluckiest man in Japan, as he constantly draws the worst hands and tiles in every game —Gaining him the nickname of "Million Shanten Man"—, meets and consequently challenges a new student for a game, getting beaten as always. This new student's name is Meronhadake Momomi, a busty woman who has the best luck in mahjong.

After this encounter, Momomi and Souta hang out together, playing mahjong sometimes, meeting all types of people, then later getting involved in affairs pertaining to the competitive mahjong world.