By Emmy Iyer(04 May 2011)
Kasthuri Maan movie starts with a mature Arun Kumar (Prasanna), now a collector of the district. The story is narrated in a flashback, where his father, Pazhaniappan wants Arun to get married. His father used to be a rich film producer and had borrowed money from a rich person but is unable to repay his debt. The rich man wants his daughter to get married to Arun Kumar. Arun does not want to get married.
Umashankari (Meera Jasmine) and Arun study in the same college. Uma is a lively, mischievous girl on campus, but at home, faces acute poverty and takes up various odd jobs to take care of her house as well as to keep away from her sister’s husband, who makes advances towards her. In the meantime, Arun Kumar’s father attempts suicide because he is deeply in debt. Umashankari steps in and helps Arun who is preparing for I.A.S. exams. She does everything to ensure that he becomes an I.A.S. officer. He in turn, promises to marry her and rescue her from her situation. However Uma, after an unfortunate encounter with her brother-in–law, lands in prison, and how the couple finally manages to re-unite is brought out in an impressive climax.