Restaurant to Another World Volume 1: 09/14/20
Restaurant to Another World Volume 1 by Junpei Inuzuka and Katsumi Enami (Illustrations) is an isekai set inside a Western style restaurant. Every Saturday when the restaurant is shut in Tokyo, the bell over the door creates portals across the countryside of an alternate world — one with magic, dragons, faeries, elves, and so forth.
This particular light novel reads more like a series of connected short stories. Most of the chapters are from the point of view of a customer — often on their first trip through the door. A typical chapter will include who has found the door, where they were when they found it, and what they end up ordering.
As the novel progresses, individual characters are shown together to give a better, richer sense of what the alternate world is like.
If you've seen the anime of the same title, all the stories in volume 1 will be familiar. I have volume 2 on hand and will be reading it soon.