I'm not sure specifically as I haven't read it in detail. But generally, it might be about a room that has some sort of special connection to a dungeon, perhaps serving as a rest stop for adventurers. Maybe it details the experiences of those who use the room in relation to their dungeon - exploring activities.
You could try looking for it in specialized light novel stores. Some large bookstores might also carry it, especially those with a good selection of Japanese or Asian literature.
The main character, of course, whose room it is. There might be dungeon monsters like goblins or orcs that come to rest in the room. Maybe there's also a magical guide or helper character who can explain the situation to the main character.
Well, it might be about a person whose room suddenly transforms into a rest area for dungeon - related characters. Maybe there are adventures that start right from this new setting in the room, like encounters with strange dungeon creatures seeking rest.
One scary rest stop story is about a couple who stopped at a desolate rest stop late at night. When the woman went into the bathroom, she heard strange scratching noises coming from the stall next to her. She peeked under and saw a pair of feet that didn't seem human, with long, claw - like toenails. She ran out screaming, and they quickly left the rest stop.
I remember a rest stop where there was a small stage for local performers. This one guy came up to sing but he was so off - key that people started to join in on purpose, singing just as badly. It turned into this big, chaotic, and very funny sing - along at the rest stop.
A common rest stop horror story is when someone enters a rest stop building that seems empty at first. But as they walk down the corridor, they hear footsteps behind them that seem to match their pace. When they turn around, there's no one there. In one particular story, a man stopped at a rest stop and went into the vending area. As he was getting a snack, he heard a low growl coming from the corner. He thought it might be a wild animal that had somehow gotten in. Another story tells of a woman who stopped at a rest stop late at night. She sat in her car for a while before going into the rest stop. When she got out of her car, she saw a shadowy figure moving towards her car from the woods, and she quickly locked herself back inside.