Sousuke Kawara

The 12-year-old son of Heitarou. First appears being tutored by Osuzu, then turns up in fight trying to get the deed to Osuzu's father's store back. Jin saves him from a beating and becomes his bodyguard.

Takes matters into his own hand after his father refuses to get Osuzu out of the brothel, and he and Jin infiltrate dressed as an old man and a woman, respectively. They fail to free Osuzu, and the next day Susuke kills a Nagatomi who tries to molest her, precipitating a showdown between the clans. Susuke becomes the Nagatomis' hostage-wager, and is freed after Heitarou commits seppuku to atone for the murder, leaving his son as the head of the Kawara clan.

(Source: Neko-san's Guide to the Characters of Samurai Champloo)