Sosuke Abayama(Jpn. - 阿葉山宗介 - "Abayama Sosuke") is one of the ten core members of the Itto-ryu in Blade of the Immortal. Second-in-command of the Ittō-ryū. An aged swordsman who nevertheless remains one of the Ittō-ryū's most skilled fighters. A skilled political operative, well suited to handling the dōjō's administrative tasks. He is missing his right arm, and uses a concealed dagger/machete-like weapon with a strange hilt. His missing right arm is actually replaced by three chains with weights which he uses as a weapon against Giichi. He is critically injured by Giichi after an intense battle during the Rokki-Dan pursuit. In the final chapters of the manga, Giichi stumbles upon Abayama being treated by his granddaughter, making him one of the few survivors of the Ittō-ryū.