The Sky Without the Sun.

Pokchat tries to get through hard times with his goodness. He was raised by Sanao, his father and has the support of Namfon, the daughter of a billionaire who favors his family. Pokchat and Namfon's bond develops deeper and deeper. One day, Sanao mysteriously disappears. Pokchat feels hopeless but he's determined to stand up again and find his father.