畑中耕作（亀梨和也饰）是拳击界一颗冉冉升起的新星，拳击会所的所长向田（小林聡美饰）对他青眼有加，深信他在不久的将来能拿下世界冠军。

可是长期以来，耕作都无法大崭头角，这源于他唯一的也是致命的弱点：美食。一碰到食物，耕作便会如馋虫附体般，不加节制地暴饮暴食，直接导致体重飚升，丧失参赛资格。耕作明知道自己的问题所在，还是屡教不改。

为迈不过“体重”这道坎而苦恼的耕作有天终于得到了神的垂青——他遇到了安琪拉修女（黑木メイサ饰），不可思议的事发生了，被丘比特之箭射中的耕作为了能与修女交往，立下成为冠军的重誓。头一遭，耕作为爱改掉贪吃的毛病，全情投入拳击比赛中……

Hatanaka Kosaku is a talented boxer who turned pro at the age of 19, winning his debut match with a first round KO. He is talented, but he has no guts. His uncontrollable appetite is an even bigger problem. He can't put himself in the right weight class, he runs out of energy because of hunger, and he gets knocked out while his eyes are set on food at the ringside. However, Kosaku's life changed when he met Sister Angela, a novice nun in the convent near his boxing gym. She became the source of his power, and Kosaku fights only to win her heart.

Kosaku Hatanaka est un bon boxeur devenu pro à l'âge de 19 ans, mais il a subi une longue liste de défaites due à son inaptitude à contrôler son appétit, ce qui le met toujours dans la catégorie de poids supérieure. Un jour après une défaite, il se promène dans une église, dans laquelle il rencontra une nonne naïve et débutante. Il se sent immédiatement intéressé par cette dernière…

Hatanaka Kousaku é um boxeador habilidoso, mas que tem problemas em controlar seu apetite, e assim manter-se na sua categoria. Após desmaiar enquanto ficava sem comer para tentar perder peso, ele conhece Sister Angela, uma freira, e apaixona-se por ela.