A Couple of Cuckoos

Nagi Umino is a 16-year-old super-studier in his second year at Megurogawa Academy high school, and he was switched at birth. On his way to a dinner to meet his birth parents, he runs into the brash and outspoken Erika Amano, who is set on making Nagi her fake boyfriend because she never wants to actually marry. But when Nagi arrives at dinner, he finds his parents have decided to settle the hospital switch by conveniently having him marry the daughter his birth parents raised, who turns out to be none other than Erika herself!