Once in a Blue Moon 85-1 Chungdam-dong, Gangnam-gu, Seoul (강남구 청담동 85-1) On the first episode, Im Siwan was seen watching a jazz singer inside a club called Once in a Blue Moon. Well, it's actually the club's name and it is located in Gangnam District, beside the gym where Roommate's Son Gayeon trains . Actually, this jazz bar was introduced to me by a reader who shared the location for Cunning Single Lady featuring Seo Kangjoon and Lee Minjung; and personally, I find it really interesting because from the two scenes, I thought that it would be a great place to unwind. I love jazz music, after all! For the directions and questions, you can drop me a comment okay? :) FOLLOW US FOR MORE UPDATES! IMPORTANT NOTE: This post may not be 100% accurate.