Kacha was an ancient sage and the son of Brihaspati in Hindu mythology. The narrative of Kacha is mentioned in the Mahābhārata, the Matsya Purana and the Agni Purana. He was known for learning Mrityu Sanjivini Mantra but failed to bring many dead Devas back to life due to earning the wrath and curse of Shukracharya's daughter Devayani.
Kacha was sent by his father Brihaspati to learn the secret of the Mrita Sanjivini mantra from Shukracharya, the guru of the Asuras. The idea was to help the Devas with the knowledge of this secret who were about to lose the war. Brihaspati also advises him to first impress Devayani in order to impress Shukracharya, who was very fond of his daughter. Kacha follows his advice and unknown to him Devayani falls in love with him. In the meantime, the Asuras want to kill Kacha, as he might be dangerous if he learns the Mantra. Every time they kill him, Shukracharya revives him with his art on the insistence of Devayani. The Asuras finally kill him and mix his remains with alcohol and serve it to Shukracharya. Shukracharya unknowingly consumes that, and when he tries to revive Kacha, he realises that Kacha was in his stomach. He teaches Kacha the Mantra and tells him to come out. Kacha comes out by tearing his guru's stomach open and brings his life back with the help of Mantra. Kacha starts his journey back to Deva loka when Devayani expresses her love for him and asks him to marry her. Kacha tells her that she is like a sister to him as she was the daughter of his guru, equivalent to father according to Hindu Dharma. This infuriates Devayani whereby she curses him that he will not remember and never get to use the Mrityu Sanjivini Mantra during the time he needs it the most. During a fierce battle between the Devas and the Asuras, Kacha decided to use the Mrityu Sanjivini Mantra to bring back all the dead Devas to life but during this moment, Devayani's curse activates and this causes him not to remember the mantra. This brought an upper hand for the Asuras in the great battle between Devas and Asuras.
