Spell of the Swan Mark - My Hero Series

Patsakorn's father was a dance teacher and the owner of a school for poor children. When Patsakorn was very young, his father died. He was raised by a rich family who adopted him ever since. Patsakorn inherited his father's talent and decided to open a dance school. But on the opening day there was an explosion and as a result, his adoptive parents and sister died. Patsakorn blames himself for their deaths and falls into depression. Waenploy, a younger girl who's a former student of his father, tries to support him. She loves and respects him ever since she was a child but he only sees her as sister, and he has a lover already. But Waenploy is ready to stand beside him and help him realize his father's dream.