On behalf of a research study I'm doing for my grad thesis, I was wondering if
extensive reading is possible in Korean middle school classrooms.
Students are not quite prepared to think that reading could be a different way to learn English but mostly it is the exam oriented culture that prevents school teachers from giving them time to read.
Since I have zero experience in teaching, I am curious if there are school teachers who have encouraged students to read regardless of the school conventions to teach English for preparation of tests, and if the method has shown success in making them read extensively and voluntarily...........

I haven't had any luck with reading in the public school system but while I was at an academy I was able to use books quite a lot. The students were elementary level and so I chose abridged versions of classic works like Sherlock Holmes and Romeo and Juliette. The kids really seemed to enjoy the books and retained the information very well. Near the end of the semester I had the kids write their own story and many of the characters from stories we had read came back into their own story. I think reading can be very effective especially if they start at an early level and work their way up. I expect my elementary students will have a very high reading level by the time they reach middle and high school. Hopefully they will have a teacher who encourages them to continue reading.

On behalf of a research study I'm doing for my grad thesis, I was wondering if extensive reading is possible in Korean middle school classrooms.
Students are not quite prepared to think that reading could be a different way to learn English but mostly it is the exam oriented culture that prevents school teachers from giving them time to read.
Since I have zero experience in teaching, I am curious if there are school teachers who have encouraged students to read regardless of the school conventions to teach English for preparation of tests, and if the method has shown success in making them read extensively and voluntarily...........

Yes. Extensive reading is possible.

Which method are you talking about? Some methods show success. Some don't. You'll need to be more specific.

My middle school has a pretty nice little English library. Hundreds of classic stories (Like Cinderella and Charlotte's Web) condensed into 25-50 page graded readers with a lot of translated vocabulary for each page. Once a semester the students read a book and then give a short summary and read a few pages to me to evaluate pronunciation. I think it's a pretty good system, I wish I had that kind of thing in my Spanish classes when I was a kid.