There is a theory that says that Mochimitsu was fat and could not run fast, hated to be a drag and asked his grandson Nobutsuna TASHIRO to assist him in committing hara-kiri by beheading him.
一説には、茂光は肥満体であったため思うように走ることができず、周囲の足手まといになることを嫌い、孫の田代信綱に懇願して介錯されたともいう。