A cool club idea that you might want to consider would be a cheer/cheerleading club. It might appeal more to girls, but some boys might be interested as well since singing seems to be popular in general in korea. Since it's low level students, you can choose the level of difficulty of the cheers, and you can learn both the words and movements (can be simple routines) to get everyone involved regardless of their english level. you can find tons of cheers online from different colleges and universities. you can even watch some movies or movie clips every now and then that showcase cheerleading. For boys, you can start some sort of sports club. for example, if it's baseball, you can learn baseball vocabulary, watch clips of games, have conversations about their favourite korean teams, etc.
hope that helps or at least gets more ideas going!