Hiyori

Hiyori is a sweet, gentle girl one year older than Haru, who acts as the president of the university's astronomy club. Hiyori, like Haru, is obsessed with space - but, unlike Haru, she's obsessed with it to such a degree she thinks she might be an alien herself.

Hiyori used to be bullied in high school for her delusions, and didn't have many friends. As such, she deeply values her relationship with Haru, and she can be rather clingy.