Directed by Ivan Reitman and written by Elizabeth Meriwether (New Girl),this is perfectly crafted rom-com. Some may claim it's full of clichés and by the book. I don't find that a detriment but a positive. There's a reason why people follow the book. The great ones do rewrite the book. That's not this.

The biggest part of the formula is the two leads. Natalie Portman is one of the cutest and engaging actress around. Ashton Kutcher is the most beautiful man candy there is. Together they make a compelling pair.

The story isn't much more than boy meets girl over and over again until they finally give in to their attraction. That's when emotionally unavailable Emma (Portman) wants sex with no strings attached. There isn't any real obstacles in their relationship. It's all in her head.

Kevin Kline plays his inappropriate father. Jake Johnson plays his best friend. Greta Gerwig and Mindy Kaling plays her best friends. There's a funny bit with Abby Elliott doing Finding Nemo and a dead-on Drew Barrymore. And Emma fights like a girl Rick Moranis.

Now if only they could change the title.

Fifteen years ago, Adam Franklin (Ashton Kutcher) and Emma Kurtzman (Natalie Portman) meet each other in a colony and every now and then they stumble on each other.

In the present days, Emma is an MIT graduated doctor and Adam is the stage assistant of a TV musical show and aspirant screenplay writer. When Adam visits his father Alvin (Kevin Kline),who is a successful TV producer, and finds that his ex-girlfriend Vanessa (Ophelia Lovibond) has moved to Alvin's house and is dating him, he gets totally drunk and calls every girl in his cell phone's contact list. On the next morning, he wakes up at Emma's apartment and they have quick sex. Emma does not want to have any emotional involvement and proposes a relationship driven by sex only without romance or commitment. But love is not possible to be rationalized and the couple is affected by their behavior.

"No Strings Attached" is a romantic comedy with a silly and incoherent plot since the motives for the behavior of Emma are not well developed and she becomes an inconsistent lead character. The story is visibly inspired on the adorable "When Harry Met Sally…", with elements of Glee and spiced with sex.

However, the film is cute and the chemistry between the lovely Natalie Portman and the pleasant Ashton Kutcher make the film worth. I believe that a high percentage of viewers love Natalie Portman and it is a pleasure to see this talented actress in any movie.

Kevin Kline has a small part but is also hilarious. This is the first time that I pay attention in Lake Bell and she is really a beautiful woman performing the role of a clumsy and nerd character. However several support characters are neither funny nor interesting. My vote is seven.

Title (Brazil): "Sexo Sem Compromisso" ("Sex Without Commitment")

Natalie Portman and Ashton Kutcher have sporadically known each other since summer camp and every few years they tend to bump each other. Portman is a busy doctor. Kutcher finds out his ex girlfriend is now dating his dad, a former television star and ends up hooking up with Portman to have casual sex with each other without falling in love. In short a relationship with no strings attached.

Of course Kutcher realises that he is actually falling for Portman and wants something more in their relationship.

The film wants to be a raunchy, ribald black comedy. It is rather conservative instead wanting to go for the formulaic falling in love route. Its actually not very sexy or hilariously funny.

It wastes its supporting cast who are in effect cyphers. What is Ludicrous doing there playing the best friend type? Kevin Kline shows up for a few scene stealing performances but even he is wasted.