During the live stream, Sana expressed how much she is a fan of Red Velvet by saying that she has really been into their songs lately. But also, she mentioned that when Red Velvet's new album came out, she listened to all of their songs and enjoyed all of them as well. 

At about 2:10:00 mark in the video below, Sana can be heard speaking of Red Velvet, "I really like their song 'Hear the Sea.' When their album came out, I listened to the full album. But from the album, I really enjoyed 'Hear the Sea' when I was in the practice room. Of course, I obviously liked 'Red Flavor' as well."

Would you like to see more of Twice and Red Velvet together in the future?