Mayuko Shiraki teaches homeroom to Tohru, Kyo, Yuki, Saki, and Arisa, though her actual subject is never specified—creator Natsuki Takaya noted in an author's comment that she figured Shiraki had the vibe of a literature teacher. She's generally easygoing but has a sharp edge; she's blocked Kyo from leaving class on Valentine's Day by threatening to dye his orange hair black, and once broke up a fight between Hatsuharu and Kyo by dumping a bucket of water on them both. When some students started calling her "Mayu-chan-sensei," she jokingly demanded they upgrade to "Great Teacher Mayuko" instead. Her parents, who run a bookstore and worry constantly about her being unmarried, sometimes get her help around the shop. According to Takaya's notes, Shiraki is probably a bit sad about being female and secretly insecure about her height—though since Hatori Sohma is tall too, Takaya thought they'd "look pretty good together."
She's closest friends with Kana, and that's how she originally met Hatori, Shigure, and Ayame about two years before the series kicks off. She had feelings for Hatori but was genuinely happy when he and Kana got engaged. She briefly dated Shigure for a month, mostly as a way to deal with loneliness, and the relationship fizzled partly because he was distant. When Hatori erased Kana's memory to end their engagement, Shiraki found herself completely lost. She's never really gotten over Hatori, and she resents how Shigure keeps meddling in her life—even when his interference somehow pushes her closer to Hatori anyway. By the series' final chapter, Shiraki and Hatori are officially together, with him inviting her on a vacation to Okinawa.
Content compiled by AnimeList.moe from publicly available sources.