Because of the tragedy that happened to Nam's family. Nantawan decided to take care of and protect his family friend, whom he is very close to. They are more than a family that grew up together from childhood until Nan was 18 years old, so he asked Nam to live in America, which is far from Passapong, Nan’s father. Both study there and stay together until Nan’s return to Thailand. In America, Nam meets Fahkram at the cafe, who is the CEO of AD Group and was there for a work trip. From their first encounter, he started having a crush on her. (Source: Meehu at MyDramaList)