I read this manga but I forgot to save my data on the app I found it on, and all my mangas were lost. I found all of them again except one and I don't remember the name and I only remember a little bit of it.
The manga was about a girl with brown hair who went to this place, where the receptionist told her to go through a door and wait in the room. The girl waited and when she walked out she was in a room filled with stacked books. In the room was a prince, who I think had red eyes and blonde hair. Another young man walked in and noticed her and asked who she was. When they finally were looking at her she looked exactly like the girl version of the prince.
Before they could do anything she went back through the door and she went back to the place where she was before; only she had her normal hair and eye color back. When they went to look for her they couldn't find her.