in the current Japanese era, everyone has their own yokai, among ordinary people and royalty. However, parts of Yokohama and Tokyo are inhabited by people without a king, they live with their evil yokai which is very dangerous.

yoru is a crown prince,he has a quite rare yokai, a vampire girl. Yoru always helps the people to expel evil yokai with the help of his vampire girl, without expecting anything in return.

"hm..it looks like we must go to Tokyo again.." he said while sighing