I didn't think Techit lack love but it's just hard for him to express his feelings especially verbally. It's hard to said "I love/like you" when he never says or received it. On top of that everyone including Kaohom already perceived him as heartless so it makes it even harder.
Techit does a lot for Kaohom if we think about it. He care for her multiple times, took her in, ask his uncle Pupal to take over the orphanage place, defend her in front of his father, pick her up from Nawa's house, respect her and sleep in a different room, took her shopping, offers to take her to school, pick her up, pays for her schooling, etc. But Nawa keeps interfering and emphasizing to his dad and Kaohom that Techit is a heartless person and just wants to win which makes it even harder for them to see Techit's love. And Techit's father arranging meetings for Techit and Ratree isn't making it any better. And darn it, she thought it was Nawa that took care of her when she was sick. Poor Techit; he came back to care for her even though he had a meeting but she didn't know.
I just love how Techit walks and look. His eyes are so attractive. I hope the Kaohom sees his love soon and proves to Nawa that he's wrong.