A Couple of Cuckoos

Mixed up with another family's child as a baby, high school student Umino Nagi is finally meeting his biological parents. On the day of their meeting, he happens to encounter Amano Erika, a high school student at a prestigious and wealthy girls school. At her request, he's half-forced into pretending to be her boyfriend so she can avoid marrying her fiance....However, not only were they the babies who had been mixed up, they're also engaged to each other!