Nagi Umino, a top student at Megurogawa Academy, learns he was switched at birth with another baby. On his way to meet his biological family he runs into Erika Amano, a popular online celebrity fleeing an arranged marriage. She turns out to be the girl he was swapped with, and both sets of parents now want the two of them engaged. Caught between Erika and his long-time crush Hiro Segawa, Nagi tries to keep his grades and his composure intact.