Born in Sariwon, Korea, Empire of Japan (now in North Korea), he made his film debut in 1956 with Gyocharo (Crossroads).

"[1] Yu attended the San Francisco International Film Festival in 1963, where Variety called Obaltan a "remarkable film", and praised Yu's "[b]rilliantly detailed camera" and the film's "probing sympathy and rich characterizations.

"[2] His dedication to the intellectual side of film and interest in using film to deal with social and political issues led him to have difficulties both with box-office-oriented producers, and with Korea's military government during the 1960s and 1970s.

[1] Korean critics have said his directing style is "in the tradition of the Italian Neorealists," yet "the terms 'modernist' or 'expressionistic' [are] just as applicable to his works.

"[3] Besides his directing activities, he has taught film,[1] and made a significant contribution to Korean animation by producing Kim Cheong-gi's 1976 animated film, Robot Taekwon V. A retrospective of Yu's career was held at the 4th Pusan International Film Festival in 1999.