Yusuke Tashiro, a spirited high school student at Ye Ran High, forges an unexpected bond with a enigmatic transfer student who emerged from an 820-year slumber. Renowned for his athletic prowess and martial arts expertise, he steps in to shield classmates from bullies or confronts gang members harassing students, his nose bandage marking him distinctly. Driven by an unwavering sense of justice, he prioritizes protecting friends like Manabu Kase, even sustaining a cast after rescuing him from a car accident. His inquisitive nature pushes him to probe strange phenomena around campus, though rash decisions sometimes escalate risks.

Romantic uncertainty colors his interactions, particularly with silver-haired noble Seira J. Loyard. Seeking peer advice, he fumbles comically in efforts to express his feelings—botched basketball displays, misfiring love letters—revealing vulnerability as he navigates emotional growth.

His world collides with the supernatural when clashes involving the clandestine Union expose him to modified humans and incomprehensible battles. Facing memory-erasure protocols to sever ties to this danger, he resists initially but ultimately yields, trusting his core self and friendships will endure.

Returning to routine, he preserves his cheerful outlook, rebuilding camaraderie while forging ties with enigmatic figures like guards M-21, Tao, and Takeo. Through ordinary routines and extraordinary trials, his journey weaves resilience, loyalty, and the delicate balance between mundane realities and hidden chaos.