Pooja Mathew (Nazriya Nazim), daughter of Mathew Davis (Renji Panicker) and Annie, is a naughty school girl. She has her best friends at her school Neethu (Akshaya), a flirt and Dona (Oshein Mertil), a junk foodie.
One day on her routine visit to Rachel Aunt (Vinayaprasad), Pooja comes to know the good side of a love marriage and decides to find a guy for her life. Firstly, she turns to a best figured guy at her school, Yardley, who is well known to all. Later, on a visit to a water theme park, Pooja meets Giri (Nivin Pauly), a graduate, who is into farming and social activities at her village. Pooja falls in love with Giri and believes him to be the man for her life.
On Giri's birthday, Pooja tries to confess her love for him, but Giri turns it down telling her to be a small girl and advices her to concentrate on her studies. Later, after her successful completion of school studies and entrance test, Pooja gets admission in Calicut Medical College. She reaches Giri's home to bid bye, but comes to know from Giri's mother Sumitra, that Giri is on a visit to the Shaolin Temple at China for his Kung fu studies. With much pain, she leaves to Calicut for her studies where she meets Dr Prasad Varkey (Vineeth Sreenivasan), her young and enthusiastic teacher and very soon they become good friends. On her last year of studies, she meets Giri again at her college. Will she be successful to gain Giri's love now? Rest of the plot gives your answer.
Nazriya Nazim as Pooja Mathew has given out a decent performance. Some of her expressions are worth it. Nivin Pauly as Giri has also portrayed his character well. Aju Varghese as David Kanjani, cousin brother of Pooja, is yet another good one which is sure to make you smile. Vineeth Sreenivasan as Dr Prasad Varkey, Renji Panicker as Mathew have also done a wonderful job. Rest of the actors including Akshaya, Lal Jose (Jacob Tharakan), Vinaya Prasad, Nikki Galrani have also done well in their small yet good roles.
Cinematography by Vinod Illampally is not an out of the world thing, but has some charm in it. Music by Shaan Rehman is pleasing. All the songs are well placed and BGM of the movie is soothing and energetic.
Director himself, Midhun Manuel Thomas behind the script and screenplay of the movie have managed to give out a movie worth watching. Though the story is told from the female side, it has a lot of cliche stuff and it doesn't boast of any surprise elements and goes in a narrow linear way where we can easily predict what will happen next. Also, the makers of the movie could have trimmed the second half which did lag at parts.
On the whole, Om Shanthi Oshaana is enjoyable with its share of happiness factor, one liners and some decent performances.