Popularly known as Sanu ‘Mash’ — a term used to refer to male teachers — began his career as a school teacher in his home town of Alappuzha. A post-graduate degree holder in Malayalam, Sanu later taught at various government colleges. He spent the most number of years at Maharajas College in Ernakulam, where he made a name for himself and became loved by a generation of students.

After retiring as a professor in 1983, Sanu became the president of the Purogamana Kala Sahitya Sangham, a body of pro-Left writers.

In 1987, Sanu contested Assembly elections from the Ernakulam constituency as a Left-backed Independent candidate and won. Although he did not contest Assembly elections after that, Sanu remained a leading light for the progressive movements in Kerala.

He was a literary critic since 1960, and also authored around 80 books in various streams of literature. He left a lasting imprint as a biographer of notable figures such as social reformer Sree Narayana Guru, poet Changampuzha, novelist Vaikom Muhammed Basheer, critic M Govindan, social reformer Sahodaran Ayyappan and writer Kesari Balakrishna Pillai. The biographies were a window into the socio-political and cultural life of 20th-century Kerala. Sanu’s writing was particularly influenced by the philosophy of Narayana Guru.

Sanu had been active in the literary world even in during last few years of his life. During the pandemic period, he authored several books, including the biography of Kesari Balakrishna Pillai.

He had won several accolades, including the Kerala Jyothi Award — the highest civilian award given by the state government.