When Devtaa and Asur were still fighting for supremacy, Devtaa appointed Angiras Brihaspati as their Guru and Asur appointed Bhaargav Shukraachaarya Jee as their Guru. Shukraachaarya  Jee was a good friend of Dev Guru Brihaspati Jee and a great devotee of Vishnu that is why he always used to teach Bhakti to Asur. And for the same reason Prahlaad, Bali, Baanaasur like Bhakt have been in Asur family.

Shukraachaarya Jee knew the art of making dead people alive while Brihaspati Jee did not. So as the war went on Shukraachaarya brought most dead Asur alive in Dev-Asur war. Since Dev Guru Brihaspati did not know the art of making dead people alive, Devtaa lost many Devtaa while Asur were not dying. So Devtaa decided that somebody should go to Shukraachaarya Jee to learn this Vidyaa. Brihaspati's son Kach was chosen to learn this Vidyaa from Shukraachaarya, so he was sent there.

Kach went to Shukraachaarya Jee's Aashram and said - "I am the grandson of Maharshi Angiraa, and the son of Dev Guru Brihaspati, I implore you to accept me as your disciple. I promise you to live as Brahmchaaree and serve you for 1,000 years." Shukraachaarya Jee got very pleased with the humility of Kach, so he accepted him as his disciple. He said - "I will treat you as I treat my old friend Brihaspati. I feel honored to have you as my disciple." Kach started his studies. He used to serve his Guru with a great care. In the meantime he took a great care of Shukraachaarya's daughter Devayaanee also. 

Thus 500 years passed. When Asur came to know about the real reason of his coming to their Guru, they got scared of being Devtaa more powerful than them. So they killed Kach. One day when he was grazing cattle Asur killed him and fed him to wolves. In the evening when cattle returned home, Devayaanee didn't see Kach. Devayaanee who was now in deeply love with Kach got very alarmed and worried and asked her father to do something about him as she feared that he was killed. She said to her father - "Please use your knowledge, and bring back my Kach, I cannot live without him."

Shukraachaarya who himself was very fond of Kach saved his life. He recalled all his pieces by his Vidyaa. They came out of the stomachs of wolves tearing them apart and he put life back in them. After a few days Asur again killed Kach and on Devayaanee's request he again breathed life in his dead body. The third time Asur killed Kach and burned his body. Then they took his ashes, mixed in wine and requested Shukraachaarya Jee to drink the wine. Shukraachaarya Jee didn't know anything about Kach's killing so he drank it.

When Kach didn't return in the evening, Devayaanee again requested him to make Kach alive. As Shukraachaarya read the Sanjeevanee Mantra, Kach spoke from Guru's stomach that he was in his own (Guru's) stomach and could not come out of the stomach as it would kill his Guru. Shukraachaarya said - "Son, you are a great ascetic and very dear to me and my daughter. If you are not Indra and if you are a Braahman then I will teach you Sanjeevanee Vidyaa. And I know that you are not Indra, because only Braahman can survive in my stomach for so long. I will teach you this Vidyaa, so that you can come out of my stomach and then you can breath life into me."

Kach said - "I have lived in your stomach, so I am like your son. You have taught me Sanjeevanee Vidyaa which is like Amrit (Ambrosia), so I am your disciple. I will behave like a good son and a good disciple because those who do  not respect their Guru fall in Hell."

Shukraachaarya Jee was very displeased with himself at drinking wine so he prohibited wine to Braahman and that they would acquire the sin of Brahm Hatyaa (killing of a Braahman) if they did drink it. Kach did the same as he was told. He breathed life in Shukraachaarya after coming out of his stomach. 

He completed his 1,000 years and now he was ready to go home. As Devayaanee was in love with him, she proposed for her marriage to him and take her along. He said - "Sister, I have lived in the same stomach from which you are born that is why I am your brother. Besides I cannot marry you since you are my Guru's daughter and it would be a great sin to marry Guru's daughter.

On his refusal she gave him Shaap that whatever he had learned from her father, it would be of no use to him for the purpose he learned. Kach accepted her Shaap and said that he would teach this Vidyaa to others for the benefit of others.  He further said - "You did not consider that I was bound with my rules of conduct and gave me Shaap just like that therefore no Braahman will marry you." And he went home and taught this Vidyaa to others for the benefit of others.