Nenji Yoshioka works as the boilerman for the Enohana Bathhouse, a role that keeps him busy maintaining the facility that sits at the heart of the community. A quiet and somewhat unassuming figure, he harbors a romantic crush on the current owner of the bathhouse, Kotomi Hiyama, though his feelings are largely unspoken. The most notable aspect of his personality is an extreme, almost uncontrollable reaction to fire; whenever he sees flames, he flies into a berserk rage, a behavior that functions as a recurring comedic element throughout the story. In terms of his role, Yoshioka is a supporting character who provides local color and occasional slapstick relief. His key relationship is with Kotomi, as his admiration for her motivates many of his quieter moments. There is no indication of significant personal development or special abilities beyond his professional skill with the bathhouse boiler and his peculiar berserk state, which remains a running gag rather than a character arc.