"Yumemiru Danshi wa Genjitsushugisha" centers on Wataru Sajou, a high school student who once harbored grand dreams of becoming a hero in a fantasy world, inspired by his childhood love for stories and games. Over time, however, he grows disillusioned with his fantasies and adopts a pragmatic, reality-focused mindset, distancing himself from his imaginative past. This shift in perspective creates a rift between him and his childhood friend, Aika Natsukawa, who remains deeply attached to the shared dreams they once cherished.

Wataru’s transformation into a self-proclaimed "realist" leads him to prioritize practicality over idealism, often clashing with Aika, who continues to believe in the magic of their childhood aspirations. Their dynamic becomes strained as Wataru’s newfound skepticism contrasts sharply with Aika’s unwavering optimism. The narrative explores their evolving relationship, delving into themes of growing up, the tension between dreams and reality, and the emotional complexities of reconnecting with one’s past.

The story also introduces other characters who influence Wataru’s journey, including classmates and friends who embody varying degrees of idealism and realism. These interactions further highlight the central conflict between holding onto dreams and embracing the practicalities of adulthood. As the series progresses, Wataru is forced to confront the consequences of his rejection of fantasy, questioning whether his pragmatic approach has truly brought him fulfillment or if it has merely distanced him from meaningful connections.

The plot unfolds through a mix of introspective moments, interpersonal conflicts, and lighthearted school life scenarios, balancing emotional depth with relatable, everyday experiences. Wataru’s internal struggle serves as the driving force of the narrative, as he navigates the challenges of reconciling his past dreams with his present reality, ultimately prompting him to reevaluate his beliefs and relationships. The series presents a thoughtful exploration of the transition from adolescence to adulthood, emphasizing the importance of balancing idealism with realism while staying true to oneself.