Meaning of the movie
Spoilers follow:
Jun-young (the adjunct professor) is a poor romantic idealist attracted to Yeon-hee (the expedient calculating lover). He wants her to love him for what he is; she treats him like a mistress; they love each other, but it can't last, because they've prostituted their relationship.
What does it mean?
She's South Korea.
He's North Korea.
Her husband is the United States.
His clueless student are the clueless nationalist Korean students romantically attached to the North.
He depends on his family (China).
They're both failures.
His turtles keep dying (there's no food).