How Sethu, on learning that he is terminally ill cherishes the short time he has to live and takes it upon himself to unite the lovers forms the rest of the story.

Neerkumizhi marked the directorial debut of K. Balachander who earlier worked as a screenwriter and it was based on his stage play of the same name.

[6] Sowcar Janaki, Nagesh, Major Sundarrajan and V. Gopalakrishnan, who were part of the play, returned to the film adaptation.

[10] Balachander wanted Sirkazhi Govindarajan to sing the song "Aadi Adangum" as he felt that "his emphasis on certain words and letters always produced the effect required.

[14] Writing in Sport and Pastime, T. M. Ramachandran named it his favourite Diwali release of the year because "it blazes a new trail in screen entertainment", while calling it better than the original play.