There is a lovely natural, unforced quality to this sensitive British cancer drama directed by 29-year-old Connor O’Hara. It’s a gentle, melancholy film about a man in his early 20s who has watched his best mates go off to uni while he’s stuck at home getting treatment for incurable testicular cancer. It’s based in part on O’Hara’s own experience of losing a friend young, which might explain his film’s low-key, unassuming style, and how few cancer movie cliches it regurgitates (for the most part).

Sex Education’s George Somner is Sid, who has been living with cancer for three years and hasn’t got long left. He’s gentle and thoughtful, shaped perhaps by getting a terminal cancer diagnosis so young. Tara Fitzgerald plays his mum, a hippyish singer who gave up touring with her band when Sid got sick; Geoff Bell is dad.

Now Sid’s four best mates are back in the village after their finals for what will be his last summer. There are some relaxed and utterly convincing scenes towards the start, with them all doing nothing, messing about, winding each other up. The movie gets more conventional when Sid decides to create a huge bonfire to give his mates something to remember him by. A romance with flaky-seeming dropout Lily (Mia McKenna-Bruce) also feels a bit obvious.

That said, what a confident little film this is. Somner’s understated, observant performance as Sid is terrific. And unusually for a film about a young person with a terminal illness, there’s not a bit of glamour to his sickness; Sid has the posture of a person who is in pain and physically deteriorating. The film deserves points too for its insights into male friendship, showing that men can be sensitive and intimate with each other (there’s a lovely performance by Wilson Mbomio as Sid’s bestest friend Diggs). By not trying too hard to be heartstring-pulling it’s a film that leaves a lump in the throat.

• Kindling is released on 21 April in UK cinemas and digital platforms.