Anna Suehiro, a teenage fashion model, possesses distinctive features: medium blue-gray hair with purple highlights styled in a Beatles cut, longer sections framing her shoulders. Her teardrop-shaped eyes exhibit deep lavender or purple coloring, accentuated by long natural lashes against a pale complexion. Professionally, she models diverse fashion styles, yet personally favors kawaii clothing during downtime—a contrast to her serious public demeanor.

Introduced through Maho Nitori, Anna belongs to a modeling agency alongside Maho and other teens. Her personality reveals contradictions: publicly outgoing and amiable during shoots, privately introverted with social unease around strangers. Peers perceive her as cool and calculating, yet underlying kindness surfaces beneath this exterior. Unintentionally, her standoffishness isolates her.

Anna's dynamic with Shuichi Nitori evolves markedly. Initially, she expresses disgust toward Shuichi's gender expression, calling them a "freak" upon witnessing their cross-dressing and dismissing it as "weak" fashion. Repeated interactions shift her stance, particularly when Shuichi seeks Anna's skincare advice. During a drugstore encounter, Anna offers guidance, forging a connection that deepens into mutual attraction. They date, with Anna initially accommodating Shuichi's public presentation as a girl.

Societal pressures and Anna's struggle to process Shuichi's identity cause a temporary breakup. After self-reflection, Anna reconciles, recommitting to support Shuichi. A pivotal moment occurs when Shuichi faces severe bullying after attending school in a female sailor uniform; Anna reacts with intense distress, crying uncontrollably. This catalyzes her full acceptance of Shuichi's identity. In an emotional exchange, Anna acknowledges Shuichi's authenticity, stating their presentation "actually suits" them. She reveals Shuichi was the first to intimately know and date her despite her reserve. Shuichi reaffirms enduring love, solidifying their partnership with implied long-term commitment.

Anna frequently visits the Nitori household, bonding with Maho. Her Japanese name, meaning "quiet, calm, peaceful at the water's edge," contrasts her complex emotions. She spends significantly on clothing and enjoys modifying garments for her style. Her journey traces a transformation from superficial judgment to empathetic support, culminating in unwavering partnership with Shuichi as they navigate future transitions together.