Edit: apparently this is a very common form of Japanese storytelling called an isekai. There are 8 billion people in this world, no idea can be original. And sometimes you miss out on things many other people know. I’m clearly one of today’s lucky 10000.
The important difference is that if it’s an Isekai you get a harem and your story is less interesting than wet paper mache. If it’s a Narnia then you get Sunday school dressed up as fun.
You’re really not into this type of fiction, I get it