Snehmoy Chatterjee (Rahul Bose) and Miyage (Chigusa Takaku) are pen pal friends who develop a deep and emotional relationship. Eventually, the pair exchange wedding vows through letters. Seventeen years pass but they never meet, yet the bond of marriage is strong between them. This unusual relationship is tested when a young widow, Sandhya (Raima Sen), comes to stay with Snehmoy along with her eight-year-old son Poltu. Snehmoy and the little boy bond and the arithmetic teacher discovers the joy of palpable bonds and fatherhood. He also develops an inexplicable thread of understanding with Sandhya too.