Devayani
Devayani was daughter of Shukracharya the preceptor of the demons. She fell in love with a student of his father. His name was Kach. When Kach was leaving the Gurukul (a kind of residential school in which students live with their teachers), the beautiful Devayani asked Kach to marry her. However, Kach refused to marry saying that it would be incest to marry the daughter of a Guru, since Guru is like a father, and his daughter is like a sister. She felt insulted and cursed him that his knowledge would become powerless when he would need it most. Kach also cursed him that no Brahman would marry her.Devayani and her companions were once went to bathe in a lake. They had put their clothes on the bank of the lake where they were mixed up due to blowing of the wind. Her clothes were mixed up with the clothes of the demon king Vrishparva's daughter Sharmishtha. They quarreled with each other. Sharmishtha slapped and threw her into a well.
King Yayati, who was hunting in the woods, by chance happened to be thereafter, pulled her out of the well by holding her with his right hand. Devayani asked him to marry her because he had hold her hand. Yayati refused saying it was not possible because he is a Kshatriya and she is a Brahman. She remained in the wood thinking that it was not possible for him to go in the city where Sharmishtha lives, until her father came there to take her back. Devayani went back only after getting Sharmishtha as her maid.
Yahati ultimately married Devayani on her request with her father's permission. Yayati gave a promise to Shukracharya that he would never invite Sharmishtha to share his bed. She bore him two sons - Yadu and Turvasu. However, she came to know after some time that Yayati had also children begotten on Sharmishtha. In an anger she left Yayati and went to his father. Yayati also followed her. On hearing the breach of promise her father Shukracharya cured Yayati to become prematurely old. Yayati the begged his forgiveness which softened Shukracharya, who said he could regain his youth if someone would exchange his youth with his old age.