Sai Lohit (2018)

Krai comes from a family of soldiers and has spent most of his life fighting in wars for his country. Dao is the youngest daughter of a village chief. Krai's older brother marries Dao's older sister, sealing the connection between both families. Krai meets Dao as a young girl and spends a lot of time taking care of her, until he's called away to defend the border. Years later, Krai comes back to realize that Dao has grown into a young beautiful maiden.