Here’s a biopic about a world-changing faith leader, a man who has published 2,500 books – according to his website – including accounts of his seances with the ghosts of world leaders. (Available to buy on Amazon: Margaret Thatcher’s Miraculous Message – An Interview with the Iron Lady 19 Hours After Her Death.) If you’ve never heard him, Ryuho Okawa is the founder and CEO of Happy Science, a religious movement that claims to have 11 million followers worldwide; some call it a cult. Now Okawa has executive-produced a long and incredibly leaden drama about himself written by his daughter, Sayaka.

If you’re going to make a film about yourself called Immortal Hero, hiring an actor with knee-wobbling charisma should be your number-one priority. But lead Hisaaki Takeuchi plays a self-help author called Makoto Mioya – an obvious stand-in for Okawa – with a blank-faced and catatonic presence. When he’s rushed to hospital after a heart attack, Mioya is told he won’t make it through the night. But he miraculously cures himself with the power of his mind. It turns out that Mioya has been visited his entire life by celestial spirits (they look like flickering holograms from an 80s kids’ TV series). Now these spirits command him to fulfil his destiny as the chosen one by unifying world religions. So Mioya abandons the self-help racket and branches into the lucrative business of religion.

The movie features some catastrophically bad acting and it’s frankly laughable in places – scenes set in London during a terrorist attack are hopelessly amateur. You could write the whole thing off as a silly vanity project but for some vile anti-medicine messaging. Preaching to followers, Mioya declares that people are responsible for their own ill health, making themselves sick by negative thinking. “All the illnesses can be cured be keeping a bright and positive mindset. It’s possible to heal yourself,” he tells the crowd, with the energised delivery of a man selling funeral cover. I’m not sure there’s shovel big enough to dig through this garbage.