In the Heat of the Sun (1969) on Netflix

The story of four teenagers in Beijing during the Cultural Revolution.

MA Xiaojun, a teenager boy, enjoying 100% freedom, grew up brutally in Beijing in the special days of cultural revolution. With nothing to do in schools, he began to sneak into strangers' homes using a self-made key. One day, he opened a door, entering the house of MI Lan. Without any notice, Mi came back home early, making MA nowhere to hide but under the bed. He saw the well-shaped young girl changing and naturally, as a teenager boy, he fell into the puppy love. Without any agenda or expectation, he tried to court the girl... Time passed away, young boys and girls changed. When looking back at the days of puberty, it seems the Sun shined strongly everyday. And the heat of the sun, though far fading, can still be felt in the memories of the people of that generation. Long story short, it is a Chinese version of the sorrows of younger Werther.

—Xuguang Deng