Doronpa is an American Obake from Texas who now lives in Japan alongside his human companion, Kaminari. His light pink body features properly divided legs and a large, detachable red star on his stomach; this star is the source of his Obake powers. Beneath it, a Star and Stripes design signifies his American heritage.

He possesses advanced transformation abilities, allowing him to shapeshift into various objects and people—a skill contrasting with Q-Taro's inability to transform. Doronpa demonstrates notable intelligence and proficient motor skills. His favorite food is hamburgers.

A primary rivalry defines Doronpa's relationship with Q-Taro, fueled by U-ko's admiration for Doronpa's intelligence, which sparks Q-Taro's jealousy. Doronpa delights in deliberately annoying and mocking Q-Taro during leisure time. Periodically, he exploits his transformation power to impersonate Q-Taro, causing mischief during Q-Taro's visits to the Obake world.

Despite this antagonistic behavior, Doronpa experiences loneliness and possesses an underlying kind-hearted nature, facilitating his connection with Kaminari. He shows affection for P-ko, Q-Taro's younger sister, though Q-Taro frequently interrupts his attempts to visit her. Doronpa's social circle includes O-jiro, U-ko, Shota Ohara, Tsuyoshi Saigo, Kizao Kiza, Yoshiko Koizumi, and Hakase.

Character development reveals Doronpa's capacity for consideration, such as temporarily assuming Q-Taro's form to maintain a presence among their human friends during Q-Taro's absences, demonstrating concern for others beneath his mischievous exterior.