Serialization of the Syosetu web novel with the same title.
 
Kazuhiro Kitase's main hobby is sleeping. Ever since he was young, he would enter a world within his dreams and go on exciting adventures. As he grew older, he became acquainted with a female Elf and the two have now been united through a Dragon's brand! As he wakes up one day, he notices a familiar figure sleeping next to him...the Elf girl from his dreams?! Join Kazuhiro on his new adventures through Japan with the lovely Ms. Elf!
 
(Source: J-Novel Club)

Kazuhiro Kitase's main hobby is sleeping. Ever since he was young, he would enter a world within his dreams and go on exciting adventures. As he grew older, he became acquainted with a female Elf and the two have now been united through a Dragon's brand! As he wakes up one day, he notices a familiar figure sleeping next to him...the Elf girl from his dreams?! Join Kazuhiro on his new adventures through Japan with the lovely Ms. Elf!
 
(Source: J-Novel Club)

Ms. Elf is intrigued by Japanese culture?!
 
Working adult Kitase Kazuhiro’s hobby is sleeping. Ever since he was a child, he’s had exciting adventures in the mysterious other world he dreams about. One day, while exploring ancient ruins with an elf girl he befriended, he is unfortunately burned by the breath of a magic dragon he encounters.
 
When he awakens from his dream, an elf girl who shouldn’t be in his room is sleeping next to him… 

(Source: Crunchyroll)

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