It is the first book of Chronicles of NarniaAn adaptation of Narnia?!?!
Shame that I've never some of the books. A bit of a jump straight to The Magician's Nephew feels risky, might get spoiled a little.
Can the Barsoom series be considered isekai? After all, it's a trip to another planet, which is still in our universe, still our world. Like Uncle Andrew says here in Chapter 4. xDIn some ways Narnia was one of the first isekais. That and John Carter from mars
This is now available as chapters on “FOD Manga” from Fuji TV, which is region locked: https://manga.fod.fujitv.co.jp/books/T000024/BT000T00002400100101/I don’t know what happened to this series, but some time this year it was deleted from ebook stores like BookWalker and Amazon, which is a pity as I only ever got the first volume. It’s not like the publisher went under as BW has their other titles, nor have they lost the license as they’re publishing the Narnia novels in Japanese.