Wataru Chikushi is an inspector in SARG, the 24th Ward's security organization, and part of its Gaichi Security Force (Gaikei). He has dark brown hair and purple eyes, exhibiting an easygoing, light-hearted personality that contrasts with his serious duties. Within SARG, he holds seniority over Hana Shishido and Kaoru Shindo.

Chikushi investigates public-order threats, including pursuits of the artist group DoRed. He arrested Shuta Aoi after the KANAE System identified Aoi as a terrorist, yet later provided him with a Critical Mission Device (CMD) that presented options for Asumi Suido's consciousness within the system: perpetual sleep or complete removal.

Additionally, Chikushi supplied Aoi with documents that unlocked suppressed memories of the Takara Elementary School fire. His responsibilities included monitoring events like the 24th Ward Gourmet Festival, where he discussed funding sources with Hiroki Shirakaba.