Itsuki Hashima is a light novelist who is enamored with small sisters and writes entirely about them in his works. Despite his personality, he is surrounded by a close group of friends, including Nayuta Kani, a brilliant yet perverted novelist who is madly in love with him; Haruto Fuwa, a fellow male author whose work has seen considerable success; Miyako Shirakawa, a good friend he met in college; and Chihiro, his ideal younger step-brother who handles housework and cooking. They spend their time together playing unusual games, going on unexpected adventures, cracking crazy jokes, and celebrating one other's triumphs. However, each person must cope with their own challenges, whether it is a struggle to make a deadline or coming to terms with tragic experiences buried in their past.