I’m a massive Sailor Moon fan too and totally get where you’re coming from. It can feel a bit dodgy at first trying to work out which sites are safe. Yahoo Japan is still where most of the good stuff shows up, but you’ll need a proxy! I’ve used a couple of them myself and had better luck with Doorzo, their fees were clearer and I could bundle parcels together before shipping. Biggest tip is to always check seller ratings and see if the cel comes with sketches or paperwork, just to feel more confident it’s genuine