The True Gentleman(2013)

Rang, a hardworking slum boy, becomes the assistant to Praewa, a spoiled heiress forced to run her family’s gemstone business. As the company faces crisis and her boyfriend leaves her, Rang helps save everything while juggling his duty to care for Koi, a blind orphan he loves like a sister. In the end, Praewa realizes Rang is the one who truly loves and supports her.