Vasanthan (S.S. Rajendran) goes to America for higher studies. During his absence, his widowed mother (C.T. Rajakantham) manages their glass factory at Salem with the help of a Manager Balu (T.K. Ramachandran), who has a relationship with Vasanthan’s niece Kokilam (M.N. Rajam). Since Vasanthan’s mother does not understand the factory’s working and management, Balu brings everything under his control and swindles the company by various means.
Vasanthan returns to India after a few years. He lands at Bombay en route to Madras to reach Salem. There he meets a hotel boy and through him, he realizes the need to understand the life of a worker before becoming the owner of a factory. He informs his mother that he would be coming after two months as he has to go on another tour, but lands in Salem as a worker named Varadhan. He joins the factory with the help of Valli (Devika), who works in the factory along with her father. Slowly, he understands all the misdeeds of Balu in managing the factory and also his niece Kokilam’s relationship with him. Meanwhile, he and Valli fall in love. Vasanthan’s mother becomes desperate for her son and starts spending money to trace him. Vasanthan decides to reveal his true identity and goes out of town.
Balu has an eye on Valli; when she does not accept his lecherous advances, he throws her and her father out of the factory quarters. They leave in search of Varadhan, who has left Salem. When Vasanthan returns, his mother becomes happy. He meets the workers and promises changes as he now understands the misdeeds of the manager. Gradually, he starts addressing all the workers’ issues. Manager Balu is kept in his place and brought under control. Unable to accept his reduced status and being under excessive control, Balu starts spreading rumours that Vasanthan is not the real owner; an imposter Varadhan has come as Vasanthan. Even Vasanthan’s mother starts doubting this since Vasanthan (who was fond of Kokilam before going abroad) is not behaving as before with her.
Now Vasanthan proves that he is the real owner and exposes all of Balu’s misdeeds. With the help of a cycle-rickshaw puller, he traces Valli in Madras (who had gone there in search of him), brings her back, and marries her.
Mudhalali had super hit songs. ‘Earikkarayin meley poravale pen mayile...’ became a folk song in villages and remains popular even today. The other popular songs were ‘Engirindho vandhan en idhayam kavarndhar...’, ‘Enga mudhalali thanga mudhalai...’ and ‘Pakkuvamai kudumbatthan...’
[from the book Pride of Tamil Cinema: 1931 to 2013, by G Dhananjayan. Blue Ocean Publishers, 2014]