Height: 177 cm (5'10")

Okabe Rintarou is a first-year student attending Tokyo Denki University and calls himself a Crazy Mad Scientist. He acts like a villain​ but is rather immature as he frequently shows traits of Chuunibyou syndrome despite being a grown-up man. After enrolling in university, he established a laboratory in Akihabara named the "Future Gadget Research Establishment", where he invents gadgets which tend to be of little use. He often speaks to himself on his cellphone, often not making any sense. Supposedly, he has very few friends that can understand what he's talking about.

The phrase he uses to end conversations, particularly with himself, is "El Psy Kongroo" (エル・プサイ・コングルゥ).