"Lee Yong-Soo" (Hangul: 이용수); also known by his stage name "Mill" (Hangul: 밀) is a South Korean artist under 8D Entertainment. He debuted as a member of OnlyOneOf in 2019 and is the rapper of the group. Mill was born on March 30, 1999 in Nam District, Gwangju Metropolitan City, South Korea. He is the eldest sibling in his family, having one younger sister. He attended Jobong Elementary School and Sungui Middle School in Gwangju, South Korea. Mill has been passionate with sports from a young age,