WWith its exuberant spirit, ketamine jokes and a prominently displayed pair of pale buttocks smeared with bluntly anti-British sentiment, the fictional origin story of Irish rap group Kneecap (who play themselves) probably won’t be for everyone. But its combination of the profane and the political, its incendiary humour and snappy editing make for one of the year’s most energetic viewing experiences, and possibly one of the funniest.

West Belfast drug dealers Liam and Naoise, part of what Liam’s wry voiceover describes as “the Truce generation”, were taught from an early age by Naoise’s republican father (Michael Fassbender) that “every spoken Irish is a bullet for Irish freedom”. It’s a message they’ve taken to heart: now the boys use the language like a brick to throw at the police. This brings them into contact with JJ Ó Dochartaigh, a music teacher at an Irish-language school who is enlisted as a translator when Liam refuses to speak English during a police interrogation. JJ sees potential in the scribbled Irish verses in Liam’s notebook, and before long Liam, Naoise and JJ have taken on the stage personas of Mo Chara, Móglaí Bap and balaclava-clad DJ Próvai respectively.

Rich Peppiatt, making his feature directorial debut after directing one of the band’s videos, brings a manic, irreverent energy to the film, with scrawled animation that looks like graffiti on toilet doors brought to life. But the driving force is the band, and performances that, while not exactly polished, are packed with bad-boy charisma.