出身空手道世家的港日混血儿平川真理，因丧父、失恋而一蹶不振，在杜汶泽饰演的师傅地狱式训练和激励下越战越强，最大敌人原来是自己。本身是空手道高手的杜汶泽当上导演不再搞笑，化身监制、导演、编剧、主演、武术指导，执意拍摄武术搏击严肃题材，邀请自己师傅、空手道七段的仓田保昭和武术爱好者欧锦棠上场，拍出独有韵味。执导筒犹如拾起空手道袍，纯粹想挑战自己。Half Japanese Hong Kong girl Mari Hirakawa who succeeds karate school after tragic death of her Karate master and father encounters ex-karate student, ex-yakuza Chan Keung who also succeeds the half of her father's karate dojo. Then, Chan Keung retrains Mari for being a true heritage owner of the karate school.