Kō Kirishima is the son of Junichi Kirishima, the director of a detention facility. He is the creator of Mother Light, a significant asset within the deadly survival game known as Tasūketsu. In Part 2 of the story, Kirishima becomes a close aide to the Queen, a key figure in the game's hierarchy. Using the privileges granted by Mother Light, he actively participates in eliminating eligible voters, thereby furthering the Queen's objectives. His background as the son of the facility director gives him a unique position within the setting, and his creation of Mother Light demonstrates technical or strategic capability. His motivations are not explicitly detailed, but his actions align him with the Queen's cause, making him a significant supporting antagonist in the latter part of the narrative. His key relationships include his father Junichi Kirishima and the Queen, whom he serves loyally. Kirishima's development is marked by his transition from being the creator of Mother Light to an active enforcer for the Queen. His notable ability is his creation and utilization of Mother Light, which provides him with special privileges to eliminate opponents.