Tomojiki Koyu

Koyu's individual personality receives little development. Her established role places her among the Public Morals Committee members dedicated to enforcing Hakoniwa Academy's regulations.

Like the committee's other Enforcers, she operates within an organization willing to use force when ordinary disciplinary measures fail. The manga does not establish enough independent material to assign her more specific traits without speculation.

Koyu has no individually named Abnormality or supernatural skill established in the manga.

As a Public Morals Committee member, she participates in enforcement work under Unzen's command, but her personal combat capabilities are not developed enough to define a distinct fighting style.

Koyu appears as part of the Public Morals Committee during the period when Unzen's Enforcers become involved with Medaka's Student Council.

Her presence helps establish that the committee extends beyond its more prominent members and includes numerous students responsible for carrying out day-to-day disciplinary work.

She later appears in recollections and group scenes involving the Public Morals Committee, but she does not receive a substantial independent arc.

Myouri Unzen is Koyu's chairman and the leader of the Public Morals Committee.

Fue Yobuko is Koyu's senior within the committee and Unzen's second-in-command.

Harigane Onigase is another Public Morals Committee member who serves alongside Koyu.

Medaka Kurokami comes into conflict with the organization to which Koyu belongs when the Student Council opposes the Enforcers' violent methods.