I’ve watched all the parts up to now, plus the Rohan specials.
I’m surprised part 6 is coming to Netflix, they’ve yet to add 4 or 5.
For anyone who wants to get into it, each part is it’s own separate story with it’s own cast. First part I watched was 4, and I didn’t miss out of anything major for not seeing the other parts first. In general, I’d recommend 4 as a starting point, as it puts the generational conflict aside for a strange summer in a small town that doesn’t effect the rest of the world.
To quote a review for Part 4 “rather than grounding the show’s pallet in any semblance of sanity, Morioh is a town exploding with eccentric color choices  who’s pallet swims and flows to match the emotion and intensity of a given scene.”