Nailed it.

When most of Indonesian teenagers are trying to learn Korean language from K-pop and K-drama, a woman at one corner of a market at Gimhae, South Korea, fluently speak in Javanese.

A video shared by Muhammad Ali Psht Mbhilong captioning 'Buying kitchen needs, got a belly laugh, (she is) so fluent speaking in Javanese.' immediately went viral.

The woman's nationality is still unidentified, but one netizen said that she is a Vietnamese.