Leon

In late 2017, Leon, also known as Donghyun, participated in the JTBC reality show MIXNINE as a trainee from NH Media. Unfortunately, he was eliminated in the seventh episode, which was aired on December 10. On July 21, 2021, Interpark announced that they had established a subsidiary label, Interpark Music Plus, for their idol group production business.

It was also revealed that the label is preparing to launch a new male idol group within the year. On August 10, Leon, along with fellow members Eunil and Yechan, were revealed as the second group of trainees. On November 30, a new profile photo and film were released with Donghyun now going under the name Leon.