Arata, the legend

the long version

Forced to pose as a girl, Arata, the last in the matriarchal Hime clan, is about to undergo a ceremony making him princess when he is framed for murdering the current princess and forced to flee. Then, a desperate wish to be elsewhere causes him to switch places with Arata Hinohara in modern-day Japan, leaving Arata to deal with a bully and life in a new high school while Hinohara finds himself in the past and running for his life.