The previous name of Daisai was Dadhi Patna, which was then under the Bahiri Mutha Pargana. The legend has it that due to the scarcity of water and widespread salinity in ground water during that period, every family had to have their own water pond in which rainwater from the rainy season would be stored for the year long consumption. When a newly wed son of a villager wished to start a family with his bride in a separate household than that of his father, the old man being willing to gift him a pond hired a few hired hands as diggers. After a few days of digging, the hired hands unearthed an object that seemed like the part of a huge wooden structure. They could not immediately recognize the structure as the most it was still hidden in the soil, mud and earth. Persevering day after day they finally uncovered not only the said structure but a hidden treasure: gold and silver coins, idols and precious gems along with it. In the full view the wooden structure was recognized as the
deck beam of a ship which had been probably sunk a long time ago, when the area had been submerged under the sea water of the Bay of Bengal. In the native language of the villagers (which is different from both Bengali and Oriya, yet is influenced by both the languages) the deck beam had been called 'Sai'. After this incident the village was called by its new name - Daisai - 'Dai' being the easier and aberrated form of the Sanskrit name Dadhi and 'Sai' being the deck beam of the sunken ship. ==Demographics==