One of the few male Sekirei seen other than Shiina. He is was once an 'S Plan Guardian', one of the five members of the 'first generation' Disciplinary Squad. Mutsu carries a sword with him but has never drawn it. His ashikabi (patner) is Hayato.The few times he has been in action, he has been shown to slam the butt of the scabbard to the ground creating shockwaves and large fissures in the ground, suggesting that he may possess earth-based powers. (Source: Wikipedia)