Chouten Gui: Path of the Predator

After a devastating childhood tragedy leaves a 12-year-old boy, alone and struggling to survive, he wanders through a city that seems to have no place for him. Quiet, observant, and unusually fast, he keeps everyone at a distance-until he meets Takeshi, an energetic and mischievous boy who refuses to leave him alone.
Their unlikely friendship becomes Raiko's first connection to another person after losing everything.
But as Raiko grows older, the world around him becomes darker. The skills he develops to survive gradually transform him into something far more dangerous.