Sethu (/seɪθu/) is a 1999 Indian Tamil-language romantic tragedy film, written and directed by Bala in his debut.

Sethu, released on 10 December 1999, initially began running as a single noon show in a suburban theatre, but gradually built up audiences through word-of-mouth publicity.

The story begins with Sethu winning the Student Union election, followed by celebrations and a fight on campus.

Just as things seem to improve, Sethu is attacked by the brothel goons for trying to shut down their business, and violently plummel his head against a rock, severely damaging his brain.

He becomes thin and is shaved bald, wearing a torn shirt and shorts in the ashram and chained to the walls.

While the brain damage eventually heals, determined to meet her, Sethu escapes successfully and reaches Abitha's house, but he is too late when he notices a crowd of people mourning and sees her corpse, learning that she has committed suicide.

After working as an assistant director under Balu Mahendra for seven years, Bala decided to make his directorial debut and wrote a script loosely based on an incident involving of one of his friends who had fallen in love, lost his mind and ended up at a mental asylum.

[7][8] To prepare for the character, Vikram shaved his head, thinned down to half his size by losing 21 kilograms and grew out his nails and even exposed himself under the sun for hours for skin darkening as the script demanded it.

Bala did not want Vikram to accept any other offers during this period to maintain the continuity of his looks and asked him to cease working as a dubbing artist.

Vikram and Bala's then assistant, Ameer Sultan, pled with the producer to return, with filming resuming in January 1998.

[3] Cinematographer R. Rathnavelu said he gave the asylum scenes a predominantly green tone for the intense psychological impact.

[10] The film ultimately released on 10 December 1999,[19] and initially began running at a single noon show in a suburban theatre, but gradually built up audiences through word-of-mouth publicity, becoming a sleeper hit.

[20] Malathi Rangarajan of The Hindu wrote, "AN AWARD winning performance by Vikram, a clear storyline, taut screenplay, powerful dialogues, crisp direction, superb background score – Sethu offers all these and much more".

[25][26][27][28] He was reportedly a strong contender for the National Film Award for Best Actor in a Leading Role but lost to Mohanlal.

K. Jeshi, a journalist for The Hindu, placed it in the category of films which propagates social issues, like Kaadhal (2004), Veyil (2006), Mozhi (2007) and Paruthiveeran (2007).

[10] Owing to its success, the film was remade in Kannada as Huchcha (2001),[32] in Telugu as Seshu (2002),[33] and in Hindi as Tere Naam (2003).