TV-Series
Description
Yū Kusaka experienced anomalous childhood snowfall with friends Hime and Izumi, unknowingly exposing them to parasitic Ayakashi entities. This granted him latent supernatural abilities. Izumi died mysteriously two years before the main events, profoundly impacting Yū. Her death coincided with the day he planned to confess his feelings, causing him to sink into prolonged emotional withdrawal, listlessness, and apathy. He lost his will to live, becoming isolated, though he occasionally used emerging psychokinetic powers for minor personal gain.

A deep-seated childhood promise to protect both Hime and Izumi drives his actions after Izumi's death, fueling his sense of duty despite emotional struggles. His Ayakashi, Ryuu, manifests as a dragon-like entity representing the strongest known Ayakashi, associated with destruction and rebirth. Ryuu's power activation and intensity directly correlate with Yū's emotional state, particularly anger or rage, often triggered by threats to those he protects.

His relationship with Eimu Yoake begins contentiously when she becomes his reluctant bodyguard after Ayakashi users target him. Their bond deepens as the conflict progresses. Yū discovers Eimu caused Izumi's death, complicating their dynamic. Further revelations show Izumi's consciousness, memories, and emotions transferred into Eimu during their fatal encounter, enabling Eimu to control two Ayakashi: Akuro-ou and Satori. This duality forces Yū to reconcile his lingering attachment to Izumi with his growing connection to Eimu.

Throughout the conflict, he confronts multiple Ayakashi users commanded by antagonist Kare, who seeks Ryuu's power for his ambitions. These encounters force Yū to refine his abilities and confront unresolved trauma. His development involves transitioning from reactive anger and self-doubt to proactive protection, though he frequently struggles with communication, inadvertently pushing away allies like Hime and Eimu during tense moments. His protective instincts sometimes manifest as lashing out or solo threat handling, reflecting ongoing difficulty processing grief and guilt.

After the central conflict, he continues navigating the burdens of being an Ayakashi handler. The sequel introduces new characters like Hime's cousin Kikuri Shirakami, who initially views Ayakashi as inherently evil. Yū's interactions demonstrate his evolved perspective on coexistence, influencing others to reconsider their prejudices. He remains committed to safeguarding both human and Ayakashi-afflicted individuals, upholding his childhood promise while forging new bonds shaped by loss and acceptance.