Recs if you like The Twelve Kingdoms Book 1 - Shadow of the Moon, Shadow of the Sea: Part 1 (Novel)...

The books accredited, by 🔗 this article, with redefining the isekai genre bit by bit. I was unable to find Warrior from Another World (1979) by Haruka Takachiho, considered to be the first catalyst of the Isekai genre in Japan.

Isekai can be translated to mean “other world” or “another world.”