如果有妹妹就好了。

「如果有妹妹的话就能拥有最棒的人生了，为什么我却没有妹妹呢……？」

专写妹系作品的妹控小说家羽岛伊月，身边聚集着各式各样不同个性的人物。有天才变态作家可儿那由多、女大学生白川京、插画家屁桃，以及鬼畜税务师大野艾希莉等等。

伊月等人虽然各自有着不同的烦恼，但还是一边写着小说，玩着电玩，喝着酒，申报所得税，过着喧闹的日常生活。

在一旁温暖守护着伊月等人的，是伊月的继弟千寻。然而，千寻竟藏着一个天大的秘密……

欢乐又锥心，由天才、凡人与怪咖所展开的多重路线青春恋爱喜剧，现在开演！

Itsuki Hashima is a light novelist obsessed with little sisters, strictly focusing on them when he writes his stories. Despite his personality, he is surrounded by a tight circle of friends: Nayuta Kani, a genius yet perverted novelist who is in love with him; Haruto Fuwa, a fellow male author whose work has seen considerable success; Miyako Shirakawa, a good friend that he met in college; and Chihiro, his perfect younger step-brother who takes care of the housework and cooking.

Together, they play strange games, go on spontaneous journeys, crack silly jokes, and celebrate each other's successes. However, each individual must also deal with their own issues, whether it is struggling to meet a deadline or coming to terms with traumatic events buried in their past.

[Written by MAL Rewrite]