Yūri, known as Jin Hazama in his parallel world, hails from an alternate Japan dominated by Princess Kotoko's oppressive rule. After his father's death, he crosses into another dimension with a singular objective: eliminate Kotori Izumi, believing her death will shatter Kotoko's tyranny in his homeland. His counterpart in the primary universe is Shin Hazama, a high school student who withdrew emotionally following his mother's childhood death.

Shin, closed off since his loss, relies on the steadfast support of his childhood friend Kotori. Jin's arrival directly threatens this bond as he targets Kotori due to her connection to Princess Kotoko. Driven by personal loss and a vigilante ethos to dismantle his world's oppressive system, Jin sees Kotori's elimination as essential.

His journey involves confronting his alternate self, Shin, and navigating the moral complexities of interdimensional conflict. Jin's resolve to challenge authority defines his path. Interactions between Jin, Shin, and Kotori underscore themes of identity, sacrifice, and the far-reaching consequences of choices across realities.

Kotori's dual role—as Shin's vital support and Jin's mission target—intensifies the conflict between worlds, positioning her at its center. The narrative traces how Yūri/Jin's background of loss and rebellion shapes his decisions, leading to confrontations that test his convictions and force a reckoning with the broader impact of his actions.