"It's not that I hate my sister. I want to be someone she can absolutely rely on. That's right, I have asked my mother many times to give me a little brother. Even after I became a student, that feeling didn't change... Until the day it became a reality in an unexpected way..." Hyaaaah, Koto Nechin's full-blown chuunibyou! This is a very serious problem, so Mr. Ikeda, the homeroom teacher, will do something about it. Well, for example, I could be Koto Neechan's little brother lol. What's this, there's Mio Neechan too. Ah, it's the season for non-stop romanticism.