1000 yen a night

In Tokyo and Osaka ,I have experience to stay in Dormitory For 1000 円 a night.I also want to stay other 47 prefectures,such as in kanto, kansai, or kyushu region For 1000 円 a night. your comments/websites are Highly appreciated.

Very hard to find except Okinawa.

Use Google, "dormitory" is same sound "ドミトリー", "1000Y" is 1000円 (Sen Yen).

Make a local friend while traveling.
Japanese young guys are shy mostly they won't attacked when you slpeep.

Maybe try couchsurfing or wwoofing? Aside from that, your only real option in that budget range is camping. I don't think you will be able to find any paid accommodation for less than 2000-2500 yen per night.

https://www.couchsurfing.com/
https://www.wwoofjapan.com/main/index.php?lang=jp

How about in a cardboard box under the train tracks? Can't get much cheaper than that.