Kim Kye‑hoon, known professionally as Crown J, was born in Seoul on 12 November 1979 and is a South Korean rapper. At fourteen he moved to the United States for education, later attending California State University before returning to Korea to complete mandatory military service. Crown J debuted in 2006 with the singles "V.I.P" and "Kevin is a Playboy" from his first studio album One & Only. The following year he released his second album Miss Me? and the track "I'll Take Her"; he also collaborated with singer Lyn on "Lovin' You". In 2008 he appeared as a virtual couple with Seo In‑young on MBC’s We Got Married and together released the digital single "Too Much". The same year he contributed to projects with Navi, Bae Seul‑gi, Park Jung‑hyun and Lexy. In 2009 Crown J joined other hip‑hop artists for the collaborative album Bluebrand: 12 Doors and founded his own label, Flyboy Entertainment, before touring the United States. He released the single "I'm Good" featuring Lee Hyun‑do. Crown J continued to produce music under Flyboy.
