"“He didn't humiliate my physical appearance, rather he gave me a beautiful nickname……….Nilavae!!!” Vennila's love sprouted on Surya who is bright and striking like the Sun, but being an unattractive girl she least expected that he would also like her. They become adorable lovers with opposite physical appearances, but fate befalls and Surya disappears from her life all of a sudden when their intense love leads her to carry their child. She eventually leaves her house at Ooty being guilty of her pregnancy before marriage and has been discovered by her childhood friend, Poornima at Coimbatore. Did Surya cheat Vennila or is there a strong reason behind his disappearance? Poornima is a stunning lass who suffers from a peculiar infirmity and strongly believes that she is not suitable for marriage but to her surprise she meets the Sun of her life, Suraj, who is ready to accept her ignoring her weakness. Along with him and her other friends, Indhu and Cyrus, she tries her level best to unite Vennila with Surya. Finally did she succeed in uniting the Sun and the Moon? “HE IS THE SUN AND I'M THE MOON” is a sensational love story of both Vennila and Poornima who faces different complications in life."