Aoi lost her parents and younger brother in tragic circumstances when she was young. She was lucky enough to survive and has been hiding in the underground ever since.
While society believes her to be dead, she moves unnoticed through the dark alleys of Tokyo and, under the protection of the yakuza, investigates the true circumstances that led to the death of her family.
In the process, the unusually quick death sentence of an 18-year-old catches her attention. She decides to help him and tries to save him from execution.
At the time, she had no idea what kind of waves this rather spontaneous decision would make in the aftermath... or did she?