沼淵 竜造

The delinquant leader in 1996 and 1999, seems to want some bad things to Tsukumo.
His war symbol is a dragon.

He is the older brother of Torazou, He died in a motorcycle accident 3 years before the "present time".

It is for this reason that Torazou understands Tsukumo's sorrow when his sister dies and seeks to help him.