Kogane are shikigami created by the ancient sorcerer Kenjaku to serve as the administrative interface and living rulebook for the Culling Game. They are small, white, floating beings with skull-shaped heads, cylindrical bodies, and wings, each possessing a black tail and unique visual characteristics that often mirror the player to whom they are assigned. As creatures of pure function, the Kogane lack personal ambition, moral reasoning, or a traditional personality; their sole motivation is the cold, absolute, and impartial enforcement of the game's rules, making them an inescapable symbol of the system itself.

Their role in the story is vital, as they are the sole link between the game master and the players. Every individual who enters a colony barrier is assigned a Kogane, which acts as their guide and overseer. The Kogane is responsible for explaining the rules upon entry, confirming participation, and announcing points earned for ending the lives of other players, with non-sorcerers worth one point and sorcerers worth five. They mediate the most significant mechanic of the game: a player who accumulates one hundred points can petition through their Kogane to add a new rule. These beings also function as a global announcement system, simultaneously broadcasting any rule changes across every colony so no player remains uninformed of the evolving landscape.

The Kogane possess a range of notable abilities that expand as the game progresses. They can act as a transparent scoreboard, displaying the names, current point totals, and colony locations of all participants, which shifts the game into a highly tactical environment. They facilitate the direct transfer of points between willing players, a function that enables crucial alliances and strategic workarounds to the game's lethal demands. When a player fails to earn points within the set timeframe, the Kogane enforces the penalty of cursed technique removal. Their interaction with incarnated sorcerers is particularly telling of their rigid logic: the Kogane recognizes the vessel's body as the official player but will obey whichever consciousness is currently in control of that body.

In terms of key relationships, the Kogane are bound to Kenjaku as their creator and master, but their primary connection is a strictly functional one with each Culling Game participant. A player's relationship with their Kogane is purely that of user and tool, yet it is an inescapable partnership that highlights the arc's themes of control and identity. The Kogane themselves do not undergo personal development or growth; they are static entities. Instead, their functionality evolves directly in response to the new rules added by players, allowing their role to shift from a simple scorekeeper into a complex tool for strategy and transparency. They remain a constant, neutral presence within the chaos, embodying the terrifying efficiency of the Culling Game and grounding its abstract mechanics in a tangible, ever-present form.