Long back, devotees of Lord Vishnu including the sages and the rishi muni's performed penance for Lord Vishnu and did tapasya day and night. Since, they were on fast for days together, there body had turned to skeleton. A king named Uparisiravasu was once passing by the forest when he happened to see these sages. He was blessed with the Astakshara Mantra a powerful mantra which could defeat anyone. Since, they were hungry; they began cutting the paddy crops and by mistake started hurting these sages too. Looking at the scenario, Lord Vishnu himself appeared in front of the men in the form of a small boy and started fighting them. The entire army could not overcome the strength and agility of the boy. Seeing this, the king used his powerful Astakshara Mantra on the boy in order to defeat him. However, the mantra lost its power. It was then that the King realized that this boy was none other than Lord Vishnu himself. He worshipped him and begged pardon on his behavior. The lord was pleased and gave darshan to the king in the form of Neelamega Perumal. Later on, he built a magnificent temple with the help of the greatest sculptor Vishwakarma and since then the Lord resides here and blesses his devotees.