Miyashita, Kamiyama, Yonehara, and Nagata were part of D.A.N.K. (Daisuke Asakura New Kids), a performance troupe produced by Daisuke Asakura. In 2001, they were selected as members for Run&Gun through an audition television program called "Study Park!!" On July 4, 2001, they debuted with the song "Lay-Up!", which was used as an opening theme song for "Study Park!!" Their second single, "Ready Go!" was released on August 29, 2001 as the theme song to a Lotte commercial. Their third single, "Twinkle Starlight", was released on December 5, 2001, as the ending theme song to the television series "Danmaru! Heroes".