【OSHI NO KO】 — Ending Explained

The overarching mystery reveals that Ai’s killer was not merely an obsessed fan (Ryosuke), but a proxy directed by Hikaru Kamiki, Ai’s former lover and the biological father of Aqua and Ruby. Kamiki is a serial psychological predator who targets brilliant stars in the industry to steal their brilliance.

Aqua discovers his paternity through DNA profiling with stage actor Taiki Himekawa, confirming their father's Lala Lai origins. Meanwhile, after discovering Gorou’s skeletal remains in Takachiho, Ruby's innocence shatters; her star-eyes turn pitch-black, and she adopts Ai’s manipulative charisma to pursue vengeance herself.

To expose Kamiki publicly, Aqua orchestrates the biographical film 15-Year Lie, casting Ruby as Ai and Kana as her fellow idol. In the climax, recognizing that legal avenues cannot stop Kamiki's predatory loop, Aqua executes a mutual-destruction gambit, ensuring Kamiki's demise while sacrificing his own life. Aqua dies having freed his loved ones from the cycle of trauma, and years later, Ruby performs at the Tokyo Dome as Japan's top idol, carrying Ai’s and Gorou’s dreams with authentic joy.

The narrative invites several multifaceted readings:

• The Anti-Idol Critique vs. The Love Letter: Some interpret the story as an indictment of idol agencies and toxic parasocial commodification, while others view it as an empathetic tribute to the resilience of performers who bring light to people's lives despite grueling conditions.
• The "Lies as Salvation" Thesis: Ai’s claim that "lies are love" can be interpreted either as a tragic rationalization of emotional dissociation or as a philosophical defense of art itself, where fiction (the lie) allows human beings to access emotional truths they cannot otherwise express.
• The Inevitability of Inherited Fate: The story can be read through a deterministic lens, where the sins and unresolved grief of the parents dictate the lives of their children, who must choose between breaking the cycle or being consumed by it.