OVA
Description
Kōki Nanjō attends Ayanagi Academy as a second-year Musical Department student in Class 2-MS and Team Sazanami. Previously in the academy's middle school, he shared first-year classes with Ageha Riku. Middle school peers called him "Sei," while close friends used "Kou" during his tenure as class representative and third-year student council vice-president.

Standing 182 cm tall with wavy gray hair and cardinal red eyes, Nanjō maintains a calm demeanor, typically wearing his school blazer unbuttoned. His training outfit includes a black zip hoodie with white trims worn open over a signature-colored t-shirt, black pants, and dance shoes. This composure offsets Kitahara Ren's impulsiveness, though Nanjō harbors a competitive streak, confidently pursuing roles like Alexis' shadow and relishing when others underestimate him—finding amusement in incidents like Kuga serving bitter melon juice or classmates struggling during fruit-harvesting auditions.

Outwardly charming and polite, Nanjō often mitigates Kitahara’s rash actions but reveals a playful, observant side when entertained by minor chaos. Self-assured, he states he "pretty much likes himself as it is," experiences little stress, and considers challenges manageable. He prefers Southeast Asian cuisine and drinks, enjoys walking or train travel, and recalls childhood visits to his father’s courtroom as a favorite location.

During Ayanagi’s Halloween festivities, Nanjō carves jack-o’-lanterns after Futaba Taiga and Saotome Ritsu distribute pumpkins. Recruited for their First Dorm prank alongside Ageha and Hachiya Sō, he conducts reconnaissance by visiting the dorm under the guise of meeting Kitahara. When Ageha and Hachiya’s ghost costumes (sheets with eye holes) prove unconvincing, Nanjō critiques their effort and recruits Kitahara and Tatsumi Rui to improve them. During the prank, he tells a spooky story that unsettles peers; when lights go out and "ghosts" appear, his tale is briefly mistaken for reality before the prank is revealed.

Nanjō performs in multiple academy songs: "REFLECTION" (a duet with Kitahara), group tracks "Storytellers" and "Gift ~Ageha x Hachiya x Kitahara x Nanjo Ver.~," and Halloween’s "Wanna be Scream?" with Ageha, Hachiya, Saotome, and Futaba. His teamwork involves strategic delegation, such as assigning reconnaissance and costume tasks during the Halloween prank to leverage individual strengths.

He shares history with Ageha Riku from middle school and a close partnership with Kitahara Ren. Upperclassmen Futaba and Saotome trust his capabilities, as shown when recruiting him for the prank. Pragmatic about social bonds, Nanjō questions if anything is "unforgivable," stating he wouldn’t hold grudges. Academically, he notes increased difficulty since middle school but adapts his schedule around team commitments.