Once upon a time, the birds and the beasts fought each other in a war. It was a terrible conflict, and the clever bats would side with the birds when the birds were looking victorious, and then they would become allies of the beasts when that side was winning battles. At last the war came to an end, the two parties reached an amicable settlement, and a great party of friendship was held. But when it came to the turn of the bats to perform in the program, their fence-straddling tactics were exposed, and everyone refused to associate with them. Since that time, the bats have been too ashamed to show their faces during the day, coming out only at night to flit silently around.
居住在京都的喜多泽家四姐妹美丽动人,除大姐彩(紺野美沙子 饰)外,其余三个妹妹茜(浅野温子 饰)、杏(沢口靖子 饰)、蓝(富田靖子 饰)都来自孤儿院。在父母过世后,彩断掉了和恋人岩城(竹脇無我 饰)结婚的念头,全力担负起照顾妹妹们的责任。大学生杏青春逼人,她成为年轻小伙追求的对象。花剑部的柚木冬悟(宮川一朗太 饰)和樱庭谅(尾美としのり 饰)同时向杏展开爱情攻势,冬悟虽然得到美人的芳心,但他的母亲却因为杏的出身而横加干涉。杏和蓝从此得知自己的身世,她们为此苦恼不已。不久,杏的生身母亲绫小路良江(入江若葉 饰)来到京都,希望女儿能与她一同生活,喜多泽四姐妹面临分离的命运。另一方面,一向乐观的二姐茜被诊断患有绝症,她和对自己颇有好感的谅走到一起,携手度过生命中最后的时光……