Ryūichi Oomiya is a fourth-year college student who joins the main trio of women during their road trip after they notice his fandom for *Ojamajo Doremi*, particularly his admiration for Onpu Segawa. This connection forms when the group spots his Onpu-themed keyholder during their travels.

He possesses slightly tan skin, brown eyes, and spiky brown hair. His typical outfit is a messy green-yellow shirt, blue pants, and olive sneakers. While journeying through Nara and Kyoto, he serves as the group's guide, utilizing his knowledge of the areas they explore.

His involvement includes accompanying the women to locations associated with the *Ojamajo Doremi* anime. During their time in Kyoto, Sora Nagase confesses her romantic feelings for him, which he does not reciprocate. Following this rejection, their group dynamic continues.