your name.

My review references the Japanese version from a learner's POV.
The anime can be seen as a classic and so is the book. The story of two young people switching bodies, a comet threatening to destroy a village and them desperately searching for each other is certainly unique.
The movie and book both match, there is nothing new that the film doesn't show. The book started a bit slow, but it got better from the middle. Sometimes it was hard to understand who is narrating as it wasn't formatted as clearly.
Language-wise it uses a lot of slang but I got used to it fast. The sentence structure wasn't too complicated either. Still, for a learner, I would consider it appropriate for high N3 or N2 due to the slang of the young people.