Arikawa Hiroshi
有川 博
| Arikawa Hiroshi有川 博 | |
| Measurements | Height: 171cm, Weight: 60kg |
| Hair | Black, Short |
| Eyes | Brown, Sanpaku Eyes |
| Body | Pale, Slim, Teen |
| Clothes | Belt, Glasses, School Uniform, Shirt, T-shirt, Trousers |
| Personality | Boku, Eccentric, Otaku |
| Role | Classmate, Friend, High School Student, School Science Club President |
| Visual novels | Side character - Hoshitsuguyo |
| Voiced by | Kazu Hajime |