K-pop rookies BOYNEXTDOOR returned with a coming-of-age EP, '19.99' — signifies the transitory phase just before turning 20. Coming-of-age stories The seven-track release documents their personal stories and emotions as they reach their twenties. WOONHAK, the youngest member, is 19 years old, while the oldest members, RIWOO, JAEHYUN, and SUNGHO, are 21. ‘19.99’ features the…