Nihon e Youkoso Elf-san.

For all of his life every time Kazuhiro Kitase went to sleep he found himself in a dream world; he has no reason to believe it is anything more than that until one day, while exploring with his friend Marie, an elf-girl, he is suddenly awakened and finds her lying in bed beside him! She is as surprised as he is. As the series continues they continue to adventure together as he sleeps and he introduces her to Japan by day.

These days it seems every other series is set in another world; as often as not featuring somebody transported from our world; this nicely reverses the cliché by having somebody from another world come to ours. This provides for a fun series that sees her as excited to see things in Japan in the way protagonists are usually excited by the fantasy world. The action is fairly well balanced between the two worlds. The characters are good, with the cast growing as the story proceeds; I particularly liked Dragon-lady Wridra; she provides some of the best laughs. Overall I'd definitely recommend this to isekai fans looking for something different.

These comments are based on watching the series in Japanese with English subtitles.