I haven't read Stephen Chbosky's 1999 novel The Perks of Being a Wallflower, which he adapted for the screen, but now I'm very keen to explore it. Chbosky has written for TV (Jericho) and film (Rent) but hasn't directed much. But while there's occasional fuzziness and opacity in this movie - it feels like it could have been a little longer with a few more gaps filled in or characters given more to do - for me, its strengths outweighed its flaws.

It's the early 1990s in Pittsburgh. Charlie (Logan Lerman from Percy Jackson & the Olympians: The Lightning Thief) is an introverted boy nervous about entering high school (it's worth remembering this is American high school, which begins in Year 9, though Lerman follows in the grand tradition of high school movies by being a few years older than his character, though not to a 90210 degree of ludicrousness).

On his first day the only person he connects with is his English teacher (Paul Rudd), who recognises the intelligence behind the quiet facade and gives him encouragement and books to read. But he'll need more than that to survive.

Fortunately, he catches the attention of senior-year step-siblings, Sam (Emma Watson) and Patrick (Ezra Miller, a very different role to We Need To Talk About Kevin). They welcome him to ''the island of misfit toys'', a circle of friends who are a little different in various ways, and it opens up a new world for Charlie, with experiences ranging from a pot brownie at a party - which leads to a personal revelation that helps draw the others closer to him - to taking part in an onstage performance during a screening of The Rocky Horror Picture Show. He also begins a relationship with his first girlfriend, Mary Elizabeth (Mae Whitman). But he is attracted to Sam.

And, inevitably, there is trouble in paradise. Some of it is easy to see coming but a lot of it comes from within Charlie himself, deriving from events from his past that are only revealed gradually, but which have had a devastating effect on his life.

The film juggles a lot of characters, some of whom, like Charlie's family, aren't developed much; but others, like the step-siblings, are very appealing: you can understand why Charlie enjoys the company of the flamboyantly gay Patrick and the extroverted Sam (Watson makes a good job of the character; she should have a decent post-Harry Potter career).

Lerman is also appealing in a difficult role; the character's nature means he has to underplay but he is very likeable. It's not hard to care about him and to feel for him when things fall apart. While it's not a perfect film, this is an evocative and heartfelt one that might resonate for many people seeing aspects of themselves, as I did (but don't ask me which).