Remember Uchida Kenji’s After School? The smartest and most entertaining Japanese movie of 2008, right? Well, don’t get your knickers in a twist, but he’s finally made another film and it’s another doozy. Key of Life is essentially a riff on Trading Places, but it takes the notion that we all play roles every day much further than John Landis ever dreamed.

Sakurai (Sakai Masato) is a 35-year-old failed actor, unlucky in love, ready to jack it all in. A random accident in a public bath-house allows him to steal the identity of another man—but he suddenly finds himself prey to the attentions of the Mob. Kondo, his new identity, is a famously ruthless fixer for the underworld. Meanwhile the real Kondo (Kagawa Teruyuki) wakes in hospital with amnesia—and has to learn to live anew as a failed actor. Perhaps fortunately, needy woman executive Kanae (Hirosue Ryoko), who has set herself a two-month deadline to get married, is on hand to help him and/or get in his way. Much of this is laugh-out-loud funny, not least because Uchida loves his characters and makes it easy for you to love them too. The whole thing is brilliantly plotted and timed (just see how Beethoven is crucial) and the all-star cast seize their opportunities with relish.

— Tony Rayns