Tian Jungkook. JK refers to high school students, and in BTS, it refers to Jungkook. He is a sports student in Class 18 of the second year of high school. He is good at arts and sports, but his grades in cultural classes are also very good. With his outstanding appearance, it is not a big deal to say that he is a famous figure. Pass. Bulletproof Boys, also known as "BTS", is a South Korean male singing group launched by Big Hit Entertainment on June 13, 2013. Its main members are Kim Namjoon, Kim Seokjin, Min Yoongi, Jung Hoseok, Park Jimin, Kim Taehyung, and Jungkook.