Formed during reality TV show Sixteen, 9-member girl group Twice is hot, hot, hot! The K-Pop stars just released debut full-length album Twicecoaster: Lane 2 following a number of extended plays. The LP’s opening track is “Knock Knock”. The music video, out for only 1 day, is already past the 10 million views milestone and received a feature in U.S. Billboard magazine. Interestingly, not all the girls are from South Korea; it is more international. Members Nayeon, Jeongyeon, Jihyo, Dahyun, and Chaeyoung were born in South Korea. Momo and Sana were born in Japan. Mina was born in the U.S. and grew up in Japan. Tzuyu was born on the island of Taiwan. Momo is the main dancer of the group, while Jihyo is the lead singer. “Knock Knock” MV embedded below. Who’s there? Think Twice.