Once in a Summer (2006)

Both stories are about people who fell in love in the past and are looking back on their love.

Tearjerkers, Korean stories about love. First is an elder movie and the second is a modern drama, but both focus on kind of forbidden love. Main characters (you'll gonna find if it's a boy or a girl) is somehow connected to North Korea. Movie and series touch politics theme too of course, but still, love story is the most important so you don't have to catch up with Korea politics, history or anything.
There are jail scenes which make our characters lie and betray loved ones, but also there are sacrifice theme present (''I can't be with you, so I'm going to leave you because I don't want to be a burden").
One of them has a happy ending, and the other one sad though...Not gonna spoil which one, watch them to find out.

Roller coaster relationship. Die hard romance. Beautiful yet not smoother. Life and love, realistic or fantasy dream, painful to choose one

Roller coaster love. Up and down, not all smooth. Love vs reality, dream vs financial hardship, romance vs surviving. Beautiful yet painful

Beautiful loving couple have to endure the pain of separation. Fate bind them together. Very romantic movie. Beautiful story, casts and OST