I just watched Sion Sono's 'The Whispering Star', for which MovieLens currently suggests no similarities. I've added some tags myself but no-one else has yet. The immediate film I'd think of it being similar to is David Lynch's 'The Straight Story'. Looking at the tags for that film, though, it seems unlikely the two films would be paired up by system tags alone because other than 'slow', the majority of the 'Straight Story' tags- eg. 'brothers', 'road trip', 'David Lynch'- will have nothing in common with the ones for 'Whispering Star'. Perhaps a 'Community Recommends' thing could help pair disparate twins like this?