Gonna be honest, I've never heard of Korean rhythm arcade games. I thought Koreans were mostly just into PC (and mobile) games. I would've thought I'd heard of this considering I read about Korean gaming culture, but apparently not enough.
Rhythm games are huge popular in Korea, probably more so than Japan right now. Units in the USA are often mistaken for Japanese, but the use of Hangul and the K-pop tunes should be dead give aways.
Pump It Up is a Korean DDR-style arcade. Round1 also seems to be bringing Chrono Circle to the US. Same manufacturer but different mechanics, it looks like maimai + Wacca.