"My Dress-Up Darling" centers on Wakana Gojo, a high school student with a passion for traditional Japanese doll-making, a skill passed down from his grandfather. Despite his dedication, Gojo feels isolated due to his unusual hobby, which sets him apart from his peers. His life takes an unexpected turn when Marin Kitagawa, a popular and outgoing classmate, discovers his talent. Marin, an avid cosplayer, is impressed by Gojo’s craftsmanship and asks him to create costumes for her. Though initially hesitant, Gojo agrees, marking the beginning of their collaboration.

The series explores their growing partnership as Gojo learns the intricacies of cosplay costume design, from sewing to fabric selection, while Marin introduces him to the vibrant world of cosplay culture. Their dynamic is characterized by mutual respect and gradual friendship, as Gojo’s meticulous nature complements Marin’s enthusiasm and creativity. Through their interactions, Gojo begins to overcome his insecurities and finds a sense of belonging, while Marin gains a deeper appreciation for the effort and artistry behind her costumes.

The narrative delves into the challenges they face, such as tight deadlines, technical difficulties, and the pressure to meet high expectations. Each project they undertake serves as a learning experience, highlighting the dedication required in both doll-making and cosplay. Supporting characters, including fellow cosplayers and friends, add depth to the story, providing additional perspectives on the creative process and the community surrounding it.

Themes of self-expression, craftsmanship, and personal growth are woven throughout the series, as Gojo and Marin navigate their respective passions and the evolving nature of their relationship. The story balances lighthearted moments with more introspective scenes, creating a narrative that is both engaging and heartfelt. By focusing on the intersection of traditional and contemporary art forms, "My Dress-Up Darling" offers a unique exploration of creativity and connection.