There is another theory on the origin that states that Katsutoyo YAMAUCHI, the lord of the Tosa Domain, forbade eating of perishable raw katsuo in order to prevent food intoxication, and instead, it was eaten only after roasting the surface disguising it as grilled fish.
また土佐藩主・山内一豊が食中毒防止に傷みやすい鰹の生食を禁じたのに対して、表面のみを焼いて焼き魚と称して食べられたのが起源とする説もある。