They're Samoan siblings from Australia. This song is in Korean. These guys can blow. They have another sister as well. Check out their Fidatrix stuff. They just lounging in their living room. They all got range. Bros name is Junez (JOONZ) probably short for Junior. Sister is Celestial.
These singers are brother and sister, there's also another sister and they all are amazing singers, but I never anticipated that they would sing in Korean given they are from Australia Samoan (i think) background...I actually love these Guys...really really have loads of respect for them, i'm deffo a fan