Daonuea

Daonuea meets Nine at a resort called The Air, in Khao Yai, after breaking up with his boyfriend, Tee. After parting ways, the two meet again at Daonuea's workplace, Lodestar Production. Though still holding feelings for Nine, he rekindles his relationship with Tee. While working together, Nine pursues him even though he is also in a relationship with his girlfriend, Praew. Daonuea fights to listen to his head or his heart. He later finds out about a past connection he has with Nine. Tee, Nine, and him all attended the same university with Nine and Tee being his seniors. Nine is assigned as his "buddy" in one of his classes. They happily exchanged anonymous messages for months because of this buddy system. After a tragedy in Nine's family, and a misunderstanding never cleared up by Tee, they did not get to meet until years later at Khao Yai.

(Source: MyDramaList)