Ichii Erisa

A bright, pure, and honest little sister who adores her big brother with a loli-punk cute vibe. She's several years younger and attends a different academy than the protagonist.

She shields her brother, who feels awkward in their matriarchal family, saying things like, “Please don't bully my big brother!”

Sadly, she's the protagonist's sole source of comfort. Her innocence leaves her vulnerable in many ways, driving her brother crazy.