Oru Kaidhiyin Diary

Oru Kaidhiyin Diary
Directed by	P. Bharathiraja
Produced by	Chandraleela Bharathiraja
Written by	K. Bhagyaraj (Story & Dialogue)
Screenplay by	P. Bharathiraja
Starring	Kamal Haasan Radha Revathi Janagaraj Malaysia Vasudevan Vijayan Vinu Chakravarthy
Music by	Ilaiyaraaja
Cinematography	B. Kannan
Edited by	V. Rajagopal
Production company	Janani Art Creations
Distributed by	Janani Art Creations
Release date	14 January 1985
Running time	152 minutes
Country	India
Language	Tamil

Oru Kaidhiyin Diary
Film score by Illayaraja
Genre	Feature film soundtrack
Length	17:36
Label	Echo

Oru Kaidhiyin Diary (English: A Prisoner's Diary) is a 1985 Tamil-language Indian feature film directed by Bharathiraaja, starring Kamal Haasan in the lead role of the protagonist. The movie was a huge success at the box office.

David tries to escape from prison, but is caught and gets his sentence increased multi-fold as a result. He gets released from prison after 22 long years and visits his dear friend Velapan. The flashback shows that David and Rosy were married and had a happy life. David is politically active in the grassroots movement and introduces his wife and newborn son to the leader of his party, the powerful politician Suryaprakasam, whom David trusted and for whom he had a high regard. The child is named James, with Suryaprakasam's blessings. However, Suryaprakasam is an evil man and was smitten by Rosy, when he saw her. He concocts a dastardly plan; he organizes a political protest that obstructs oncoming rail traffic with David as the leader, knowing David will get arrested; thereby allowing him access to Rosy.

Suryaprakasam succeeds in his evil plan. Rosy then comes to him for help in getting David released. Suryaprakasam manipulates her child away from her and then attempts to disrobe her, but Rosy escapes. However, Suryaprakasam was prepared—his sidekick threatens to harm James unless she submits—Rosy was forced to submit and come back—Suryaprakasam then rapes her violently with his henchmen's help. Shamed and humiliated, Rosy then commits suicide by hanging herself and leaves her husband a handwritten note with the details.

Meanwhile, Velapan bails out David. David, who is proud to have gone to jail for Suryaprakasam's protest, comes home singing his praises (with Velapan sobbing as he knows what happened to Rosy), until he sees Rosy hanging dead and reads her note. Upset, David confronts Suryaprakasam at his birthday function and makes a scene. Inspector Viswanathan and Dr. Unnikrishnan pretend to help David but are actually Suryaprakasam's friends. They successfully manipulate Rosy's note away from David and destroy it, thereby the entire evidence of the crime, laughing all the while at the hapless David.

The trio then frame David for Rosy's murder, lie in court and easily win the case. David gets sentenced to prison for killing his wife. He leaves his only son with his close friend Velappan, who promises to raise David's son as a hardened thug, who will help David avenge Rosy's humiliation and death, and David's wrongful imprisonment.