Heitarō's pubescent son, heir to the Kawara Clan's leadership. He is hasty and impetuous, not a surprise for his age and the shame his father has to endure. He has strong feelings for Osuzu, and intervenes when Ishimatsu comes to collect her father's business deed, succeeding only in getting her taken away, too. Joins forces with Jin to rescue her but fail as Mugen is guarding the brothel. The night after he goes to see Osuzu again and blows a gasket when a customer puts his hands on her. The man is a Nagatomi, but Sousuke does not know that when he draws his sword and stabs him to death. Heitarō commits seppuku on his account. Rikiei mocks Heitarō, while Sousuke defends him. Upon the Nagatomi Clan's defeat, he assumes his father's position.