A Little Bird (1974)

Feeling that she has no choice after failing her college entrance exam and not being on good terms with her step-father, Yeong leaves home. She spends the night with a man named Cheol whom she meets, but he turns out to be on his way to his mandatory two-year military service and leaves the next day. Yeong becomes pregnant from their encounter. Two years later, Cheol returns. He informs Yeong that he is engaged and asks for custody of their child.