NTB (엔티비; short for & previously known as NAUGHTYBOYS) is a six-member boy group under High Choice Entertainment.
Prior to their debut, the group consisted of nine members, all of whom were former members of PUREBOY. Following the departures of three, they debuted in Japan on August 3, 2016 with the single “DanCin’derella/Step By Step”. They made their Korean debut on May 28, 2018 with their first mini album Dramatic.
Source: kpop wiki