In the underground of Shinjuku's Tōyoko district, a ruthless one-on-one street mahjong scene thrives, where money and even the players' own bodies are wagered. At the center of this dangerous world is a girl named Esuka, who has earned the title of the strongest by remaining undefeated. She won her freedom through mahjong, having drifted to Shinjuku and survived by betting everything on the game. Esuka is a cold and calculating player, but as the matches escalate, glimpses of a darker side to her personality surface. The story follows her battles against a series of formidable opponents, each enforcing their own brutal variations of the game. One foe is a physically imposing man who pushes her into a "complete decision mahjong," a match that only ends when one player scores a limit hand or the other collapses from exhaustion. Another challenge is the "Doubt 1" game, where players must detect lies in face-down tiles. A recurring figure named Kurama becomes entangled in Esuka's life, and their relationship shifts as her hidden vulnerabilities emerge. The final arc pits Esuka against Ranna, a so-called princess of online mahjong who despises the street version and the girl who dominates it, leading to the first all-female showdown in the series. Throughout the narrative, Esuka's past and the cost of her unbroken streak are slowly revealed.