Yamato Akitsuki travels to Tokyo alone to study in one of the high schools located within the area. He lives in with his aunt who operates a public bath solely for the ladies in the local district and begins his normal high-school life. One day, he chances upon a girl in school and is immediately mesmerized by her beauty. He is shocked when he realizes later that the girl, Suzuka, is actually living next door to him. From then on, Yamato's ordinary life begins to change little by little.

小桀的父亲是名顶级猎人，却在他很小时就离开了他。多年后，天资聪慧生性善良的他也决定成为一名猎人，并借此去寻找素未谋面的父亲。
在考取猎人证的过程中，小桀结识了杀手家族出身的奇犽，火眼睛族的唯一幸存者库拉皮卡和想要成为救济穷人的医生的雷欧力。并且和西索，一个视强者为猎物的神秘魔术师形成亦敌亦友的关系。
经过重重考验，小桀顺利拿到猎人证，可是对与小桀来说，考验才刚刚开始。