His father, now deceased, was the most important benefactor of his encounter with dance, which was of great significance to his life, according to a film about his growth story featured in Gucci's 2019 project "The Performers."

[6] In 2007, encouraged by his father, Kai participated in and won SM Entertainment's Youth Best Contest and signed with the company at the age of thirteen years old.

[8] He made his first televised performance alongside fellow Exo members Luhan, Chen and Tao as well as other SM artists at the year-end music program SBS Gayo Daejeon on December 29, 2011.

In October 2012, Kai participated in the promotional group Younique Unit alongside labelmates Eunhyuk, Henry, Hyoyeon, Taemin and Luhan.

[10] Later in December 2012, he joined the dance group SM The Performance, along with fellow member Lay, TVXQ's Yunho, Super Junior's Eunhyuk and Donghae, Shinee's Minho and Taemin.

[13] In January 2016, Kai made his acting debut as the male lead in the web drama Choco Bank,[14][15] which achieved record-breaking viewership.

[16] In December 2016, he starred in two episodes of the special web drama 7 First Kisses which was produced by Lotte Duty Free.

[17] In January 2017, Kai was announced to be starring as the male lead in the KBS teen drama Andante, playing a high school student.

[23] On August 7, 2019, Kai was confirmed to be a member of SuperM, a "K-pop supergroup" created by SM Entertainment in collaboration with Capitol Records.

[38] On March 5, it was reported that Kai is set to release his fourth EP in April 2025, with music video scheduled to film next week.

[44] On November 1, Kai appeared in the online showcase "TUCSON Beyond Drive," a collaboration between Hyundai Motors and SM Entertainment, where he presented a music performance titled "Follow Your Hidden Light" that combines K-pop and AR technology.