Hazuki Takajo. By day, an ordinary high school girl. By night, a substitute mahjong player-for-hire. At times, she wagers not only billions of yen but even her very life on the mahjong table. Her true goal: to find her father, who was taken away when she was a child. And the only clue that leads to him… is mahjong itself. What kind of future awaits Hazuki on the path she has chosen――?