Kuzuha is Yuuta's younger sister who is in the first year of junior high school. She knows Yuuta very well, especially how he acted during his Chūniby� days in middle school as Dark Flame Master, though she always considered him embarrassing. Kuzuha got used to her older brother's delusions since she was young. (Source: Chuunibyou demo Koi ga Shitai! Wikia)