Yaowamarn lost her job so her aunt Mingkwan took her to the temple to do merit and ask for a good job. After she “wai” the monk she went outside to wait for her aunt. There she saw a girl in white who spoke in a weird language, trying to give her a small bronze coin. She refused to accept. Later Yaowamarn came to realize that she had fainted as she was walking out of the temple so she thought everything that happened was a dream. When she got home she found the coin in her pocket. That coin brought her to meet a yak. She was afraid and tried to run, but coudn’t so she had to sit there as the yak introduced himself.
Sura Mara was punished to come down to earth for having an arguement with the serpent fighting over the wishing crystal. He told Yaowamarn he has to stay with her for the full ten months that he is being punished because in the last life, she owes him. The lady in white was an angel named Nilubon Atchara. Though Yaowamarn doesn’t believe it, she has to do as follows because she’s afraid of Sura Mara in his Yak form, but she will definitely try to get him out of her life.
Source: AsianFuse Wiki)