First Costume Arc

Wakana Gojo, a shy student training to make hina dolls, is discovered sewing by his outgoing classmate Marin Kitagawa, who asks him to help her create her very first cosplay.

The First Costume arc establishes the entire premise of My Dress-Up Darling and introduces the unlikely friendship at the heart of the series. Wakana Gojo is a reserved high school student raised by his grandfather, a craftsman who makes traditional hina dolls. Wakana dreams of inheriting this delicate art and has quietly developed real sewing and sculpting skills, but he keeps his hobby hidden after being mocked as a child for liking something so unusual for a boy. He eats lunch alone and avoids attention, content to practice his craft in the school sewing room where no one will judge him. Everything changes when Marin Kitagawa, a bright, fashionable, and immensely popular classmate, accidentally discovers him sewing. Rather than ridiculing him, Marin is fascinated by his ability and reveals a secret of her own: she is a passionate otaku who loves anime, manga, and games, and she has always wanted to cosplay her favorite characters but cannot sew. She boldly asks Wakana to make her a costume. Overwhelmed but moved by her genuine enthusiasm and complete lack of judgment, Wakana agrees to help. The arc follows their first collaboration as Wakana applies his doll-making precision to a human-scale costume for the first time. He takes Marin's measurements, researches the source character, drafts patterns, and carefully constructs the outfit, learning that costuming a living person is very different from dressing a doll. Marin's encouragement helps Wakana see that his craft has value and that his passion can be shared rather than hidden. By the arc's end, the completed costume and Marin's overjoyed reaction cement a partnership built on mutual respect, planting the first seeds of a deeper bond.