Kain was born in Manhattan, New York City, New York. His mother, June, is of African American and Chinese descent. His father is African American poet, playwright, recording artist Gylan Kain, founder of The Last Poets. Kain attended Professional Children’s School. Kain attended Hunter College High School in New York and later relocated to California, attending Foothill High School; graduating in 1983. After high school, Kain returned to New York and attended New York University where he majored in film.

Kain first appeared in the 1992 film Juice as Raheem. Following roles included Roosevelt Nathaniel Hobbs in the 1994 comedy drama Renaissance Man and Marvin Cox in the 1997 romantic comedy, Love Jones. Kain portrayed golfer Tiger Woods in Showtime’s The Tiger Woods Story. In 2001, he teamed again with Juice director Ernest Dickerson in Bones (starring Snoop Dogg). Kain had a role in the 2003 blaxploitation biopic Baadasssss!.

Kain appeared as Darnell Wilkes, Maya’s (portrayed by Golden Brooks) husband on the UPN/CW TV series Girlfriends from the season 2 through the conclusion of the series. Kain replaced his Juice co-star Flex Alexander, who left to star in the sitcom One on One. Other television credits include Suddenly Susan, Friends, Blue Bloods, Living Single, Moesha, Angel, and Sister, Sister. He also played the role of Bill in the 2010 movie For Colored Girls.