Shri Singha (Skt. Shri Simha) was born in a Shocham Nakpo, a city in China to a householder family. From age fifteen, be studied the five fields of knowledge, including sanskrit grammar, astrology, and valid cognition with the master Hastibhala. One day, when traveling on the road to the city of Serling, he had a vision of Avalokitesvara in the sky, who told him that if he wished to attain enlightenment in a single lifetime, that he should travel to the charnel ground of Sosadvipa.
To prepare himself as a vessel of the Secret Mantryana, he studied the outer and inner meanings of the tantric approach for seven years with the master called Bhelakirti in the five-peaked mountains of Wu Tai Shan, in China. He mastered the tantras, explanatory commentaries, and pith instructions according to the outer and inner levels of the tantric path.
One morning, while bathing, Shri Singha had another vision of Avalokitesvara, giving him advice similar to before. Because of the difficulty of traveling to India from China, Shri Singha decided to train in the yogic ability to move swiftly for the next three years. Finally, he made the journey to India in nine days, with his body moving swiftly a yard above the ground. When he reached Sosadvipa, he requested that Manjushrimitra take him as a disciple. Manjushrimitra agreed, and prophesied that Shri Singha would recover the texts he had concealed. When Manjushrimitra passed away, he dissolved into a mass of light in the sky. Upon Shri Singha's cries of distress, a jeweled locket containing Manjushrimitra's last words, The Six Meditative Experiences, fell from the mass of light.
After he recovered the teachings that Manjushrimitra had concealed, Shri Singha returned with them to vicinity of the Bodhi tree growing in China, and there he divided the most sublime secret teachings into the categories of outer, inner, secret, and most secret unsurpassable. These were concealed in the pillar of a temple at Tashi Trigo. He then went to the charnel ground of Siljin.
He later transmitted the teachings on the Secret Mantrayana to his Vimalamitra and Jnanasutra.