Places for solo camping

Hey guys,

I would like to spend one or two days in some campsite to enjoy nature.

I am looking for something not like a family-type but rather some place with more young vibe. Since I am travelling alone, probably feel more confortable in a more relaxed place. Maybe some place near some trekking or mount. Some place not more than three hours from kyoto, so I spend one or two nights and get back.

Any advice or comments will be appreciated

Thanks!