Ryūji Ishii, a brown-haired, brown-eyed young man with a stocky frame, adhered to a rigid daily regimen of jogs to control his weight, reflecting his disciplined demeanor. His loyalty and approachable nature earned him widespread peer admiration, though he consistently declined social outings to honor his devotion to girlfriend Fuuko Sorano.

Blessed with the supernatural capacity to shrink himself to microscopic proportions, Ryūji could infiltrate pores—a skill cementing his prominence within their class. His lifelong bond with Fuuko had recently frayed under unspecified tensions preceding his demise.

Rentarō Tsurumigawa, a classmate capable of detaching his spirit from his body, murdered Ryūji via throat-slitting and stab wounds. The chaotic crime scene and an open window initially suggested Fuuko’s wind manipulation as the culprit, until evidence exposed Tsurumigawa’s exploitation of their familiarity to circumvent Ryūji’s defenses.

With strategic resolve, Ryūji used his final breath to implore Fuuko to slit his throat, framing her as a false suspect to expose the true killer. This calculated sacrifice not only underscored his loyalty but also ignited Fuuko’s pursuit of justice and escalated simmering conflicts among their peers. His legacy persisted solely through these cascading consequences, with no expanded backstory beyond the central narrative.