The group then releases two singles: 'Stress Come On' and 'Ojingeo Doenjang' (Korean: 오징어 된장). He also participated in the program Hitmaker season 1, presented by South Korean producer duo Jeong Hyeong-don and Defconn and became part of the program's project unit group, Big Byung, together with Got7's Jackson and VIXX members, N and Hyuk. In July 2014, Yook was cast as a presenter for the program, A Song For You alongside Kangin of Super Junior and Amber of f(x). In 2014, Yook appeared in the television series Reply 1994 as Sungjoon/Ssukssuk, Na-jung's little brother. In the same year, Sungjae and BTOB made a cameo appearance in hit drama ' The Heirs' episode 4 as themselves, an idol group band BTOB. He, with BTOB's Lee Minhyuk, Lee Changsub, Im Hyunsik and Beast's Yong Jun-hyung were featured in the drama OST Part 1 titled 'Days Gone By', OST Part 2 'After Time Passes', and OST Part 7 'First Love'. He appeared in 4 episodes in total, episodes 2, 6, 9, and 12. Sungjae acted as Arnold, a member of boy idol group 'Men In Black'. In 2013, Yook Sungjae started his first ever acting debut in drama Monstar (TV series) as part of the supporting cast alongside his bandmates Lee Min-hyuk, Lee Chang-sub and Im Hyun-sik. On March 23, 2012, Yook co-host SBS MTV's music program The Show alongside bandmate Lee Min-hyuk. Yook made his debut as a vocalist of BtoB with 'Insane' and 'Imagine' on March 21, 2012.

2012–2014: Debut with BtoB and solo activities Yook entered the JYP 6th Audition Final Round before joining his current agency, Cube Entertainment. On March 6, 2011, Yook also participated in the stage performance of '2011 CUBE Stars Party' with bandmate Seo Eunkwang, Im Hyun-sik, Jung Il-hoon, and supposed to be member Lee Min-woo. On August 10, 2010, he participated in the stage performance of '2010 Cube Stars Party'. He then attended Dongshin University, majoring in Practical Music. He completed his high school education at Hanlim Multi Art School, graduating in 2014.

He briefly studied for a month in England and the Philippines, respectively. His grandfather was the first to introduce red carp in South Korea, while his grandmother operated a fishing farm in Paju. His father is the CEO of an IT corporation that deals with semiconductors. Yook was born on May 2, 1995, in Yongin, Gyeonggi Province. 2.4 2018–present: 3x2=6, Yook O'Clock and Mystic Pop-up Bar.2.3 2015–2017: Acting and rise in popularity.

2.2 2012–2014: Debut with BtoB and solo activities.

Who are you school 2015 mv