An affluent medical professor, Komiya, and his bossy wife, Tokio, are to look after Setsuko, their high-spirited niece from Osaka. Setsuko is a liberated woman who does what she wants, including smoking, even though she is a minor. On Saturday, the professor does not feel like going to his weekend golf game, but his wife packs him off anyway. So he leaves his bag at the apartment of his student Okada, and goes to a bar with a friend. Setsuko traces him there, and insists that he take her to a geisha house. When she gets rather tipsy, the professor calls Okada to take her home, while he sleeps at Okada's. The wife becomes suspicious of Setsuko when she sees Okada bringing her home, and also of her husband when she discovers that he did not go golfing.
公元199X年，人类世界的最高首领因一己私欲发动战争，甚至愚蠢地按下毁灭世界的按钮。世界遭受核武器洗礼，山崩地裂，海水枯竭。部分人类虽侥幸存活，然地球上资源短缺，使得血腥纷争仍在继续。 世间传说“有北斗出现的地方，必现乱事”。
就这样，我实际上遇到了一个非常棘手的麻烦——在学校给臭名昭著的犯罪男孩吉田纯（铃木大阳配音）送讲稿！虽然我们第一次相处并不愉快，但随着接触的加深，我发现吉田纯并不像他看起来那么古怪和粗鲁。相反，在他高大的身体里，其实有一颗善良的心，害怕伤害别人。因为害怕受到伤害，他干脆完全拒绝了，这就是吉田的处事哲学。对于吉田来说，曾经被人鄙视的优等生也有天真细腻的一面。这两个人在误会中逐渐吸引了对方，在一群陌生调皮的朋友的陪伴下，甜蜜青春的校园爱情剧开始了。
