Naoki Kaga, a genetically engineered clone born from experimental procedures designed to replicate Sugiura’s mother—a woman afflicted by cardiac complications—exists among multiple flawed replicants, including Fuyuka, their truncated lifespans a consequence of imperfect replication.

Acting as an operative executing Sugiura’s commands, Naoki engages in efforts to reclaim Fuyuka after her flight from the cloning facility. His mission revolves around thwarting Ling Fei-long’s attempts to liberate her, a path that ultimately drives him to orchestrate his own demise to secure Sugiura’s objectives. This pivotal choice reinforces his function as a catalyst escalating the adversarial clash between Ling and Sugiura.

Rooted in the cloning initiative’s goal to prolong his creator’s mother’s survival, Naoki’s existence embodies the project’s ethical paradoxes. While his personal agency remains undefined, his predetermined fragility and genetic instability mirror the experiment’s perilous ambition, framing him as a tragic instrument of human hubris.