Rak Ni Chuaniran

Accidently swapped at birth, Pichaa and Pan go on to lead very different lives: Pichaa grows up with loving parents and a brother, Patin, while Pan is raised by a single parent in poverty. One fateful day, the two are returned to their biological families. Drama ensues when over a decade later, Pichaa is reunited with Patin, whom she once believed to be her brother. Things are further complicated when they fall for one another romantically.
(Source: DramaWiki)