D.O. is the stage name of the jazz singer who is starring in "The Underdog" alongside Park So-dam and Park Chul-min.
 The film is directed by Lee Chun-baek and Oh Sung-yoon and stars Do Kyung-soo, Park So-dam and Park Chul-min in the lead roles. 
Do Kyung-soo (born (1993--) 12, 1993 ), better known by his stage name D.O., is a South Korean singer and actor. 
