Rei Sugiyama struggles with historically low self-confidence, finding solace primarily in anime media. A period of social withdrawal stems from academic stress and health issues, leading to extended isolation. This isolation lessens upon connecting with others sharing similar interests, marking a significant shift toward communal experiences. Attending an anime convention becomes his first major venture into crowded public settings, an initially overwhelming experience.

During the event, an unexpected transition transports Rei to an alternate dimension—a physical realm shaped by anime enthusiasts' collective imagination and desires. Hostile entities immediately confront him, including Mave, until rescuers like Super Sylph and Sylphid intervene. Rei perceptively analyzes the situation, concluding this dimension relies entirely on sustained fan interest. He further deduces its impending collapse aligns with the convention's conclusion, evidenced by visible environmental decay.

Facing this crisis, Rei shares his personal history of isolation and realization about mutual support's value with the dimension's inhabitants. This recounting galvanizes their resolve against oblivion. When confronted by the antagonist Forgetter—a manifestation of narrative obsolescence threatening eternal forgetfulness—Rei faces a choice: return home or stay to aid the inhabitants. Initially preparing to depart, he witnesses their struggle and reverses his decision. He publicly vows eternal remembrance, even as conventional interest wanes. This declaration, amplified across real-world media, empowers the characters to overcome Forgetter. Ultimately, Rei chooses permanent residence within the dimension to prioritize its inhabitants' preservation, despite physical constraints preventing his return.