"Mr. Chu" is a song by South Korean girl group Apink. The song is their 5th Korean single and served as the lead single from their 4th mini-album Pink Blossom. It was released on March 31, 2014 by A Cube Entertainment. The song composed by Duble Sidekick. The song's music video was directed by Digipedi and released on the same day. Apink performed the song for the first time on KBS's Music Bank on April 4. The song peaked at number 2 on Billboard's K-Pop Hot 100.