Yup! I saw it with friends from the US who had never seen or read Slam Dunk before. They loved it! Although it actually takes place at the end of the comic, it's a really excellent standalone movie. You don't have to know the series and it never plays on nostalgia.

Slam Dunk is amazing. I highly recommend it, even if you don't particularly like basketball. The new movie is really excellent as a standalone film too. Not just good for animation, but truly one of the best films I've seen in ages.