Kare functions as the central antagonist, his true identity concealed, known solely as "Him". He commands Orochi, a potent snake-like Ayakashi. He methodically directs subordinates to target protagonist Yuu Kusaka, deliberately pushing Yuu to fully awaken and utilize his own Ayakashi, Ryuu. This calculated manipulation advances Kare's overarching strategy.

He publicly champions symbiotic coexistence between humans and Ayakashi. Yet his core motivations are deeply personal and destructive: healing severe injuries suffered during a past confrontation connected to Izumi Makihara's death two years prior, and consuming other city-dwelling Ayakashi to augment his own strength, exposing his self-serving agenda.

Kare's actions critically shape multiple backstories. He killed Orie Natsuhara's master and Bakeneko's handler, defining Orie's existence as a cat Ayakashi seeking purpose. His role in the events causing Izumi's death establishes the narrative's foundational conflict, profoundly affecting Yuu and Eim Yoake, whose connection to Izumi's consciousness originates here.

His influence extends through Akino Yoake, Eim's older sister, who maintains unwavering loyalty to him. Akino rejects Eim as her sister after Eim chooses to protect Yuu over aligning with Kare's faction, further isolating Eim and cementing Kare's divisive impact.

Kare operates via proxies, notably employing Heima Kajiwara to surveil Yuu. His Ayakashi, Orochi, embodies his antagonistic force, symbolizing his constant threat. Despite significant behind-the-scenes influence, his limited physical presence heightens his enigmatic nature, driving the central conflict toward its climax.