Ned (Paul Rudd) was not asking much of life, he was satisfied selling fruit and vegetables from an organic farm out in the countryside, never happier than when he was spending time with his pet dog Willie Nelson. Unfortunately, his naturally trusting nature got him into trouble when a cop in uniform wandered up to the stand he was selling his wares at and asked if he could give him some marijuana; Ned was sceptical that an officer of the law would indulge in such recreational drugs, but was eventually persuaded to hand a bag over for a small sum, whereupon the cop told him he was under arrest...
With the Weinstein Company logo at the beginning, you may well know what you were in for with Our Idiot Brother, basically an indie-schmindie comedy drama with slightly edgy humour and sincere emotional parts to leave the audience feeling they were getting their money's worth with the full range of sensations available to them within the parameters of the style. There would be the sort of actor who could appear in such things so they could stretch their thespian muscles and have a satisfying experience professionally in between appearing in bigger budget hits, which also had the bonus to the producers of raising the project's profile.
So you can see why there are those resistant to such efforts when they could come across as contrived to a specific template as any number of explosion-filled blockbusters, but director Jesse Peretz, by this point a veteran of helming television comedy episodes, managed to bring a personality to the proceedings which did more to engage. Ned could have been some dreadful hippie stereotype, but in the hands of the writers and Rudd's (mostly) placid demeanour someone more human emerged, a character who could contrast with the others who saw him as the idiot of the title simply because he wanted to get along with everyone and didn't see confrontation as a necessary aspect of life.
Of course, this makes him a terrible person to trust with a secret, since he is so into telling people what's on his mind quite often that will be something he has been told in confidence, so once Ned gets out of prison (with time off for good behaviour) he sets about accidentally making a nuisance of himself. The first problem isn't really his fault, as his girlfriend Janet (Kathryn Hahn) throws him off the farm, and most heartbreaking to him keeps the dog; as he isn't one to argue his corner very well, he can only mutter "Wow!" in exasperation and is forced to leave his best friend behind as he moves back to New York and his family, which includes his mother (Shirley Knight) and three sisters.
Those three sisters have problems of their own. Miranda (Elizabeth Banks) is failing in love and struggling to make an impact in journalism, stand up comedienne Natalie (Zooey Deschanel) seems to be in a happy relationship with Cindy (Rashida Jones) but has a wandering eye when it comes to sexual flings, and Liz (Emily Mortimer) is bringing up her two young children with husband Dylan (Steve Coogan) in as hermetically-sealed an environment as she can muster, but unable to admit how miserable she is. Ned goes to live with each one in turn, messes up in some way through his goodnatured to a fault honesty, and it seems to be one of those movies where everyone suffers some flaw or other to send the characters into dramatic situations rather than having them behave more convincingly than they might if making us laugh was not on the agenda. But then, even by the point of the inevitable redemption for them all (except Dylan, who even garners Coogan a humiliating nude scene), you do warm to them, and the life free of unnecessary friction espoused doesn't seem so bad.