Keumyong

On December 10, 2015, he made his debut in PUREBOY's sub-unit PURE-L with their first digital single "Balloons", under the stage name Ki-O. The sub-unit was later merged in the original group. He presumably left the group in June 2016.

On March 23, 2020, Ki-O, now known as Keumyong, was introduced as the first member of TOC. They are presumed to have disbanded in July of the same year due to inactivity.