Toom and Nuch have known each other since she was a child and he was a teen. He was her hero and a very dear person to her and her best friend Noo Aon. Noo Aon was adopted into Toom's family so she was like his sister. Nuch was sent to a boarding school by her father after her mother died so Nuch and Noo Aon lost touch, but she was still in touch with Toom. Years later Nuch graduates school and Toom is always by her side, but he is hiding a large secret from her. He is now married to Noo Aon as his parent's request. Toom doesn't love Noo Aon and he loves Nuch very much but he doesn't tell her. Nuch returns home to find that her father has remarried and she now has a brother. Nuch's stepmother is a very nice woman but Nuch doesn't like her and his very mean to her. As for her brother she is okay with him. Nuch goes to the mall and meets Noo Aon, she wants to introduce Nuch to her husband and Nuch is shocked to see and know that Toom is now married and he has been hiding it from her all this time. Nuch gets angry, but what's even worse is that Noo Aon is pregnant. Nuch now hates Toom and refused to talk to him and makes him jealous by using Orachun.
(Source: AsianFuse Wiki)