My kid's half Okinawan, so I want to speak & read as fluently as possible for him and my wife's family. I went to high school there too, so I been studying a long time.
I know a few Korean phrases. I hear that the grammar's very similar to Japanese. Some parts of Japan speak about 60% Korean as their regional dialect due to their proximity to Korea. You guys don't use as many Chinese characters, which looks nice. Maybe someday I'll study it formally.
Chinese was a lost cause for me. In college I had roommates for Taiwan. Would spend months working on picking up words & improving my pronunciation only to get shot down anytime I tried to use it with another person from Taiwan.