Marmalade Boy (en) is a romantic comedy manga and anime about Miki Koishikawa, a high school girl whose parents suddenly announce they are swapping partners with another couple and all moving in together. Miki is horrified to discover her new stepsibling is Yuu Matsuura, a charming but aloof boy who seems to stir up trouble. Despite their awkward start, a deep and complicated romance develops between them, tangled with jealous friends, ex-girlfriends, and the challenges of a blended family. Readers enjoy the series for its dramatic love triangle, relatable teenage angst, and the unique premise of parents switching partners, which creates constant emotional tension and heartfelt moments.