Kurayama Aya

The twin sister of Saya.
Compared to her sister, Aya is more carefree and less responsible. She prefers to play than study. Her uncle's perversion also annoys her, although she's not as strict as Saya.
Aya aspires to be an idol, and she works hard to get there.

It's a delicate time for both sisters as they progress from childhood to adolescence.
During the story, she has her first menstruation.