Kei walks into rooms where men lose everything, reads them like tiles, walks out richer. The show builds actual dread around a card game by making you understand that every hand matters because the people playing it can't afford to lose. Underground mahjong becomes the language for a kid learning that strategy and ice-cold calculation can't protect you from the people around you wanting things you can't give.

Kei walks a razor's edge between two worlds. He is a quiet high school student living on his own, but in search of a new thrill he ends up in underground mahjong parlors where money, women and even organs are on the line. His cold, stylish strategy earns him the nickname K of Ice. After beating a criminal group, he takes in an abducted girl named Amina instead of taking cash. The enigmatic Hideharu Seki then draws him toward new parlors and opponents, and a near-disastrous match against the seasoned Doujima shows Kei how much he stands to lose.