Heart-sama (ハート様, Mr. Heart) is a minor antagonist from Hokuto no Ken.
The most prominent antagonist among Shin's four lieutenants. He is an extremely fat man. His stomach absorbs the blow of every martial art, except Nanto Sei Ken. Usually he is gentle and good-natured. But, when he watches blood of his own, he runs berserk with rage and massacres those around him.
He was defeated by Kenshiro, who kicks him with enough force to dissipate all of his fat layer and reaches his fatal pressure points. His death cry was "Hidebu!." ("Debu" = "fat man")
Althought being a one-shot villain in the original series, Mr. Heart has gained his own fanbase and later appeared as playable character in several Hokuto no Ken games.