Despite being skilled at planning, NAKAWA is the most cold-blooded and untrustworthy. They prefer to hunt in small groups, but each of them always survives without caring about the others…

They established themselves as the lords of the rapids. Their strength lies beneath the waves, where they've never lost a race. They specialize in the stealthy long-range assassination..

NAKAWA live along the Snaky River, the main water resource area, which is a sewage system located outside of the big metropolis. It's also a wellspring of unsolved mysteries, such as deep-water monsters!? This causes no one to venture into this area much…