Otogiri Tobi, a second-year junior high school student, spends depressing days searching for his missing brother with his non-human partner Baku.Tobi doesn't talk much with anyone other than Baku, but one day his classmate Ryuko Shiratama suddenly calls out to him, and his daily life begins to change little by little...?An adventure story about “humans” and “non-humans” that one boy confronts!!