I like Korean music and anime.
Is there any Japanese anime with a Korean OP or ED?
I know of anime OSTs created by Korean artists but not in Korean language. Korean singing in Japanese is eargasmic for me. If you follow Korean music, you shall know about TVXQ creating three OSTs for One Piece
Also, BoA has created the Inuyasha OP. Her voice in Japanese is so beautiful, i love it!
Ao no exorcist OP was created by 2PM, i could get the kpop vibes from it when i first listened to it.
These are the only ones i know of, anime is pretty popular in Korea so i am sure there are more, feel free to do more research.
In terms of OP/Ed of an anime, it is more likely to find Opening and the Endings that is produced by Korean Artist (singing in Japanese)than featuring actual Korean songs.
In the 15th Opening of Fairy Tail, Masayume Chasing. It is sung by a Korean Singer goes by the name of BoA. Here is the link of the song in short ver https://youtu.be/G0gD9jzYtEA
As for another anime which is called Beezlebub,the 4th opening of the series is sung by a Korean Group MBLAQ, Baby U. The particular opening does has the Kpop genre like vibe.
TVXQ with One Piece”Share the World” 2PM with Ao no Exorcist with “Take Off” Secret with A Naruto Spinoff called “Twinkle Twinkle” And quite a handful of korean artist/group
Overall, It is more likely that a Korean artist would produce a Op/Ed in Japanese instead of Korean as it is usually will be as a Japanese single.
There is one I know but only a movie. Pokémon the Movie: Volcanion and the Mechanical Marvel ost is sang by the korean girl group G-Friend.
Title:Letter Inside Pocket