Tips for renting a car in Japan?

I’m considering renting a car for 2-3 days during my first trip ever to Japan.

What should I keep in mind when renting a car there?

I’m aware that I need an International Driving Permit (IDP), which I’ve already obtained. I also know that cars in Japan are right-hand drive (RHD) and that driving is on the left side of the road. Having lived in the UK, I’m somewhat accustomed to driving on the “opposite” side, so that shouldn’t be an issue.

But what else should I consider?

Are RentalCars.com or AutoEurope reliable brokers for renting a car in Japan, or should I look elsewhere?

I’m planning to pick up my rental car at Niigata Airport (KIJ), though I’m not fully set on this and could change my plans if there’s a good reason to do so.

I’m also thinking about dropping the car off at a different location, possibly Nagoya (NGO) or Komatsu (KMQ), rather than returning it to Niigata.

After dropping off the car, I’ll continue to Kyoto by public transport to visit shrines and do the usual sightseeing people enjoy there.

I’d appreciate tips from those with more experience navigating Japanese roads, especially since this will be my first time driving in Japan. By the way, what scenic routes do you recommend?

Are there other places worth visiting that are difficult or inconvenient to reach by public transport but easy to access with a car?

I don’t plan to drive in Japan’s big cities—when I return to Tokyo, I’ll rely on public transport. My focus is on countryside areas, rural scenery, small cities, and villages. What should I keep in mind for that?

Also, are there many toll roads in Japan? Are there restricted zones or penalties for “outsiders,” like the ZTL zones in Italy?

How different are Japan’s traffic rules compared to those in Europe?