梨田雅之认识了大学的学长永田一成。永田是个万年留级生，但特会打麻将。永田身上那种虚无的气质让雅之觉得很好奇，两人接触日多。于是，雅之也被拉入了麻将的世界。这是一个充满刺激的世界，令雅之沉迷不已。不久之后，雅之偶然结识了咖啡店漂亮的女招待泰子，两人坠入了情网。麻将赌博和爱情给生活注入了兴奋剂，雅之迷失在快感中，等待着他的是……

A murder mystery told in one-minute clips — one for each day of the year — filmed specifically for the SEGA Dreamcast console. It tells the story of Nao Tsunoda, a 16-year-old schoolgirl who moves to Tokyo’s Grauenheim apartment complex. One day, Nao’s life turns into a nightmare when she suddenly discovers the headless corpse of her neighbor on the roof of the house — and a chain of brutal murders continues, becoming clear that a psychopath is hunting the apartment building's inhabitants.