Kakkou no Iinazuke

Nagi Umino has long known that he was accidentally switched with another baby at birth. On the day he is finally supposed to meet his biological parents, he encounters Erika Amano, a famous social-media personality trying to escape an engagement arranged by her father. The coincidence becomes far stranger when they discover that Erika is the child raised by Nagi's birth family, while Nagi was raised by hers. Their parents decide the simplest solution is to engage the two to each other. Nagi and Erika reject the plan, especially because Nagi already loves his classmate Hiro, but being made to live together turns a relationship they intended to ignore into an increasingly complicated part of everyday life.