Can I park my campervan in Gujo Hachiman?

I will go to Gujo Hachiman by camper van and i plan to stay for a night there,,Where is the closest place to park and stay over night, thank you

I recommend "michi-no-eki" for sleeping in your car.
Free parking, 24/7 toilet,vending machine and so on.
It seems more than 5 michi-no-eki's,within 1 hour drive from Gujo-Hachiman station.
What is "michi-no-eki"?
Just go to "michi-no-eki.jp",english pages and locaton map available.

I drove almost ever prefecture in Japan with my car,
and I slept at more than 100 michi-no-eki with no trouble.
Onsen,supermarket,and michi-no-eki.... sounds good.

Unsure how big your campervan is, but there a fairly big paid car park with 24/7 toilets at Gujo-Hachiman Jokamachi Plaza bus terminal. At night the place is completely deserted, I doubt if anyone would care if you stay there all night.