They’re both orphans. Muichiro is soft,sweet and shy While Yuichiro is skeptical,bossy and has a foul mouth.Their Mother died from an illness and their father fell to death while trying to gather herbs.They’re both defendants from Yoriichi.Yuichiro is supposed to die to a demon and when Muichiro is really mad,he becomes really strong,meaning he will black out and kill the enemy with every weapon he can find,but it happens rarely.