Dr. Kiriko, a Japanese physician infamous as the "death doctor" or "Reaper’s Avatar," practices euthanasia with unwavering conviction, positioning him as both an antagonist and ideological counterpoint to a rival surgeon. His older incarnation presents a striking figure: long white hair cascades freely over pale skin, an eye patch obscuring his left eye, while a perpetual grimace accentuates his austere demeanor. He dresses in a tailored black suit and shoes, sometimes layered with a maroon overcoat and a vivid yellow bandana. A hefty suitcase accompanies him, housing the specialized apparatus central to his controversial work.

Once a military doctor in wartime, Kiriko’s exposure to countless terminally ill patients—their agonized pleas for release—reshaped his medical philosophy. These experiences forged his belief that death, administered with intent, could eclipse futile suffering as the ultimate mercy.

A younger Kiriko emerges in stark contrast: a daring, lighthearted medical student who once parachuted into perilous zones to aid the injured. This version embodies audacious idealism, prioritizing lifesaving heroics over the somber pragmatism of his later years.

Within the narrative, Kiriko relentlessly contests the dogma of preserving life at any cost, advocating instead for euthanasia as compassionate intervention. His clashes with a surgeon opposed to his methods underscore profound ethical divides, yet even adversaries acknowledge his surgical prowess and unyielding dedication to his principles.

Kiriko’s journey dissects the moral ambiguities of mercy and obligation, his interactions with peers illuminating conflicting visions of medicine’s purpose. Through these tensions, the narrative probes existential questions of agency, dignity, and the boundaries of humane care.