Acommodation for Nebuta

Hi, I am looking for acommodation for Nebuta, all AIRBNB in Aomori for the 4th of August are booked, do you know any hotel with vacancies?

If I can't book anything is it possible to sleep a while in the station and pick the 1st train in the morning? What do you think?

I don't think that sleeping in the train station would be possible. It is likely closed at night.

During the festival the city gets fully booked. You might try to see if you can register as Toyoko-Inn member from abroad. https://www.toyoko-inn.com/eng/

As far as I know if you are a member you can reserve rooms 6 months before. I would expect it to sell out very quickly after opening of this time frame.
Other hotels also might open their booking around 6 months before. So it might be that you are just slightly too early.

Enjoy your trip to Japan!

One cannot become a member of Toyoko Inn without paying the membership fees and getting the ID card with the unique member ID. That can only happen when you arrive in Japan and pay for your first night. They'll issue you a card once they take your photo.

As previous poster mentioned, you're a bit too early. So far I've booked over 100 hotels in Japan over past 4 years. From what I've experienced, most non-brand named hotels won't open reservation over 3 to 6 months ahead.

Try checking availability again early next months, and keep checking everyday if you want to stay at popular place. You might also want to try email. I have successfully booked some hotels didn't show any availability online.

If you are unable to get accommodation in Aomori, try Hirosaki.
Hirosaki also has Nebuta festival, which is not as busy as Aomori, but still worth the visit.