I is the first solo mini-album of South Korean singer Kim Jaejoong, a member of pop group JYJ. The EP was released on 17 January 2013 and is composed of rock songs, two of which were composed by Kim Ba-da from the rock band Sinawe. One of the songs, "나만의 위로" (Healing for Myself), was a soundtrack from the film Code Name: Jackal, which starred Jaejoong and Song Ji-hyo. The album was an immediate commercial success, with all 120,000 initial copies of the album selling out within two weeks. An additional 20,000 copies manufactured to cope with the high demand were similarly sold out. A repackaged edition titled Y, which includes two new tracks and two instrumental tracks, was released on 26 February 2013 and experienced similar success, with all 50,000 initial pressings of the album selling out within 24 hours of sale.
The mini-album debuted at the top of both the Hanteo and Gaon weekly charts in Korea and broke previous pre-order records in Japan. It also topped the iTunes overall chart in Japan, as well as the iTunes rock charts in nine countries. The first single, "One Kiss", which was released digitally on 8 January, topped the iTunes overall charts in Japan, Singapore, Vietnam, Taiwan and Thailand. The album debuted at number two on the Billboard World Chart.