Tomomi Saikyou, formerly Tomomi Suzuhashi, attends Hakureiryō Academy as an upper-ed student. Outwardly refined and academically gifted, she masks a manipulative and mischievous nature. She engineers compromising scenarios involving nudity, groping, or public humiliation—primarily targeting childhood friend Akiharu Hino and rival Selnia Iori Flameheart—driven by boredom and sadistic amusement, often signaled by a high-pitched giggle and shadowed expression.

Her history with Akiharu includes childhood bullying that inflicted lasting trauma. She strategically withholds critical information to manipulate events, as seen during the Hino-Khadim marriage scandal, intervening only when complications intensify. On a date, Akiharu confesses his childhood crush and past desire to marry her, surprising and embarrassing Tomomi, hinting at unacknowledged mutual feelings.

Tomomi's rivalry with Selnia extends beyond academics; she envies Selnia's bust size and popularity, frequently exposing her breasts publicly. Witnessing Selnia kiss Akiharu ignites Tomomi's jealousy, compelling her to confront her romantic feelings for him. She invites Akiharu on a date to discuss their conflicted past, though her manipulative tendencies persist despite emerging vulnerability.

Physically, she stands 162 cm tall with measurements of B80-W57-H81, fair skin, black shoulder-length hair, and amber eyes. She typically wears the red upper-ed uniform with a violet ribbon, often depicted without a bra.

Her unresolved development involves ongoing romantic tension between Akiharu, Selnia, and herself. While scheming remains habitual, her actions occasionally yield constructive outcomes, such as pairing Akiharu with Mimina Ōsawa to motivate the latter artistically.