Kai [ 카이] was born Kim Jong-in (Korean: 김종인; Hanja: 金鍾仁) on January 14, 1994 (age 20) in Seoul, South Korea. The second Exo member to sign with S.M. Entertainment, Kai joined the company after winning in the 10th S.M. Youth Best Contest in 2007, at thirteen years old. He said that it was Shinhwa who inspired him to be a singer.
Known as the group's "lead" dancer, Kai has been dancing since he was eight years old and was trained in jazz dance and ballet. He stated that his parents initially wanted him to learn Taekwondo and the piano, but he quickly lost interest in both. After watching The Nutcracker when he was in fourth grade, Kai expressed his wish to study ballet professionally. He developed his current technical expertise of hip hop, popping, and locking after joining S.M. Entertainment. In 2008, Kai made a brief appearance in TVXQ's music video, "HaHaHa Song" along with Exo-K's Suho and Chanyeol.
Kai was the first of twelve Exo members to be formally introduced to the public through teaser trailers. His first teaser was released on December 23, 2011. He appeared in twelve more trailers released in the next three months, and had his first televised performance with Exo-M's Lu Han, Chenand Tao on SBS's Gayo Daejun event on December 29, 2011. Kai graduated from School of Performing Arts Seoul in early 2012.
Kai is also associated with the promotional singing group, Younique Unit, with Exo-M's Lu Han, and S.M. Entertainment's dance group, S.M. The Performance, with Exo-M's Lay. and TaeTiSeo's Twinkle MV with Sehun.