Directed by Kunal Kohli (who directed Mujhse Dosti Karoge earlier), the film is about leading cartoonist Karan Kapoor (Saif), who creates cartoons called Hum Tum.
The duo has a new look in this film. While Saif wears his hair long, Rani has hers relatively short for some parts of the film.
Though Saif and Rani have never starred opposite each other, they have featured in J P Dutta's war epic LoC-Kargil. Rani also had a very special appearance in Saif's film, Kal Ho Naa Ho.
Hum Tum is slated for a May 28 release.