Osing (1985)

Seven-year-old girl Shin is sold off as a servant. She takes with her the 50-cent coin her grandmother gave her. However, at the master's house, Shin is accused of stealing the money and beaten. Shin escapes to mountains where she falls into a faint. Jin-ho, a student soldier, runs away from the army into mountains. He saves Shin and they live in the mountain where he teaches her how to read and fall in puppy love with each other. After the winter, Shin and Jin-ho go down the mountain. But they are discovered by soldiers who end up killing Jin-ho. Shin takes the harmonica that belonged to Jin-ho and goes home. When her father beats her and plans to sell her off again, Shin leaves in search of her mother. Shin finds her mother who is a kisaeng. Understanding that she can't stay, Shin leaves to become a servant. Learning that her grandmother is near death, Shin returns home and vows to overcome their poverty.

Unfortunately the movie Osing is not yet available on HBO Max.