One-night affair between a princess and a werewolf.
Harima was a prince of Baekje - a Korean kingdom in 7th century. But he was defeated in battle and turned into a wolf-man. He came to Japan and managed to become a feudal lord Inugami, only to unintentionally get involed in the Jinshin War.
He was imprisoned in the capital, but thanks to help from the imperial princess, he escaped and hid in a cave. One night, the (very) young princess paid him a visit… Although Harima already had a lover, he didn’t (really) resist. Next morning, they parted with each other to never meet again.
From Phoenix: Sun by Osamu Tezuka