On Wednesday MBC looked a middle school on Shinan county's Haui-do (하의도), a tiny school where grades one and two are combined and taught in the same room at the same time. Not only can't rural schools attract teachers, but there are fewer and fewer young people living in these areas to fill schools. That middle school---there's only one on the island---is actually a combined middle and high school, with 12 middle school students and 24 high schoolers according to the school website.
An hour-and-a-half ferry ride from Mokpo, Haui-do is an island of roughly 1,970 people and is the birthplace of the late President Kim Dae-jung. The island's elementary school is a little bigger with 43 students plus 13 in the preschool.
If you look around the webpage for the Shinan Office of Education you can find stats on all the county's schools current of September, numbers which differ a little from what you find on school websites. There are 831 students distributed among the 14 middle schools in Shinan, a county comprised almost entirely of islands. Looking at this map it looks like Haui Middle School, the one MBC reported on, is among the most remote.