The experience of parking in Japan varies significantly depending on where you are. Since the land in big cities like Tokyo and Osaka hold such high value, it can be harder to find and more expensive to use public parking spots.
On the other hand, rural or suburban areas tend to be dotted with big parking areas, especially near supermarkets and malls, making it comparatively a breeze to find a spot for your car.
Check out this guide for everything you need to know about parking in Japan: https://japantravelplanning.com/car-parking-in-japan/