You’re A Liar

The puppet emperor was killed by a cup of poisonous wine from the Prince Regent. When he opened his eyes again, he was forced to become a suffering high school student with the same name and surname who had committed suicide for love a few hundred years later.

The original subject of his unrequited love; that cold desk-mate and neighbour, who looked exactly alike the prince regent who had poisoned him in his previous life.

A grim and cold prince regent who needed a treasury of loving words x A wimpy little emperor who pretends to bare his fangs and brandish his claws on the surface