Siva (S. J. Surya) is an investigative scribe who shares a live-in relationship with rich and bratty Madhu (Nila).

Fun starts as the fantasy element appears in the form of their apparitional alter egos.

[2] The film was initially titled BF, an initialism of Best Friend, but Suryah was met with a protest from Tamil Protection Movement led by PMK leader Ramadoss and Dalit Panthers of India leader Thol.

After three months of its launch, Suryah changed the name from BF to Ah Aah, the first two letters in the Tamil alphabet.

He revealed that he was inspired to make the film to convey that young lovers must give each other space and wanted to showcase that attitudes towards relationships by the Indian youth was changing from the previous decade.

[11] Sify labelled it as "adult entertainment" though added he "tries hard to bring his character Shiva to life but has to go miles as far as dialogue delivery and voice modulation goes but has improved leaps and bound on the dancing front".