Touhai: Ura Rate Mahjong Touhairoku

In underground mahjong parlors, money is not always the most valuable thing on the table. Crushing debts, human organs, and lives themselves can become stakes. Among these players is high school student Kei, known in the underworld as 'K of Ice' for his expressionless calm and ability to read opponents without giving anything away.

Kei enters games where a single mistake can destroy far more than his bankroll, facing veteran gamblers willing to use deception and violence when tiles are not enough. His cold manner hides a personal reason for remaining in this world, and a girl living in his home is connected to the most dangerous part of his secret life.