Yukiho Kousaka

Yukiho is often shown doing embarrassing things when she's by herself. Despite constantly scolding her sister, Yukiho really does care about her older sister. She is the only little sister to Kousaka Honoka. It is also shown in the anime that she has a good friendship relation with Ayase Arisa, Ayase Eri's little sister.

(Source: Love Live! School Idol Project Wikia)