Younger Sister Raidou

She is a junior high school student. She's a childish girl who regards her big brother as "sorta odd guy", thus worrying her for if her big brother is able to make friends.

She has black short hair and brown eyes. She wears a white sailor uniform with navy blue skirt, white short socks, and black penny loafers.

(Source: Aharen-san wa Hakarenai Wiki)