Love Exposure is a rare achievement, at once epic in its themes, ambition and length and winningly light and playful in its treatment of them.

Yu is a teenage boy, at once an innocent and the self-styled “king of perverts”. When his saintly mother dies and his dad becomes a priest in thrall to a sex-crazed parishioner, Yu hits on a career as an up-skirt panty photographer as a way of both looking for the love of his life and committing sins he can confess to his father. One day, while dressed as a female yakuza boss, he meets and falls in love with Yoko, a man-hating tearaway who he rescues from a rumble with a gang. The course of true love never did run smooth, though: increasingly tangled family relations mean they end up as step-brother and sister, and then a real-life yakuza boss and cult leader pretending to be Yu pretending to be a yakuza boss starts a lesbian affair with Yoko, and, well, it gets complicated... but there’s comedy and romance and martial arts, and the whole thing climaxes in a psychotic, bloody frenzy.

The film's chief themes, lurking beneath all this frenetic and frequently absurd hyperactivity, are religion - its power, hypocrisies and notions of sin - and sex, with the sacred and the profane frequently mixed, as in Yu's use of ‘perverted’ up-skirt photos to find the worshippable Madonna he seeks.

The central teens are all marked by the various traumas and abuses of their childhoods, and the film's four-hour runtime allows these to play out in full. This is also a movie of yearning and adolescence, with the would-be romantic leads forging identities for themselves while seeking erotic and spiritual satisfaction. With its intricacies, satiricism and fresh characters, Love Exposure’s skipped past before you have any concept of how much of your time it’s thieved, or of the darkness it’s smuggled into your subconscious. Virtuosic stuff.