NCT U is the first official sub-unit of the South Korean boy group NCT, managed by SM Entertainment. It stands out for its unique rotational concept, where members are selected for specific songs based on the concept and sound, rather than having a fixed lineup.Debuted in April 2016 with the singles 'The 7th Sense' and 'Without You'. NCT U pioneered NCT's overall concept of limitless members and rotational units....