I don't know anything about the group, so here is info from Youtube:
This show is called 유학소녀 or UHSN means "Girls Studying Abroad" The girls (international K-pop fans) were brought to study Korean culture. This song is just a one time thing for fun, and they are not an actual girl group nor is this a debut.
The girls are from Estonia/Sweden, Ukraine, Egypt, Norway, Thaiand, USA, Russia, Japan (Erii from Produce 48), Sweden and Poland.
source: Mnet K-Pop, 대왕.