Welcome to Japan, Elf.

Kazuhiro Kitase, a working adult, loves to sleep above all else. Since childhood, he had always embarked on thrilling adventures in the mysterious dream world he frequently visited. One day, while adventuring with an elven girl he befriended in a dream, they were unfortunately incinerated together by a magic dragon's breath. Waking from the dream and returning to his room, he found an elf who shouldn't have been there...