Kotosaka, a green parrot of the Green Clan, functions as both medium and messenger for Nagare Hisui, transmitting the leader’s will through human-like intelligence and a voice that shifts seamlessly into Nagare’s own. His eyes flare with vivid green light when channeling his master’s presence. A survivor of the Kagutsu Incident, he initiated his bond with Nagare by biting the latter’s nose—an act that secured his position as the clan’s first member and elevated him within JUNGLE’s hierarchy, ranking above even Sukuna Gojo.

During the Mihashira Tower conflict, he bypassed Neko’s illusions alongside Yukari Mishakuji, leveraging his capacity to phase through solid matter and unleash targeted electrical surges to disable foes. His methods intertwine ruthlessness with playfulness, exemplified by his amused reaction to Neko’s electrocution.

As Nagare’s proxy, he relays commands and strategizes operations, appearing prominently in *K: Seven Stories*’ third film, *SIDE:GREEN ~Uwagaki Sekai~*, which expands on his JUNGLE authority and dynamics with other elites. He features peripherally in the sixth film, *Circle Vision ~Nameless Song~*.

His combat repertoire includes flight, limited lightning generation, and intangibility, allowing evasion of attacks and disruption of adversaries. Though animalistic, his dual utility as Nagare’s voice and a tactical asset cements his importance to the clan’s objectives.

His character remains static across narratives, unwavering in loyalty to Nagare and marked by sardonic independence. His origins trace unambiguously to the Kagutsu Incident and his subsequent ascent within the Green Clan’s machinations.