I'd heard that Yufugawa Canyon (Oita prefecture) had sustained some damage and it was closed for repairs but as there was no news update on their website since May I decided to head there myself to find out (with the hope that it was open so I could do some canyoning).
Eventually it is still closed, the entrances to go down are blocked. Happened to meet a fine lady who normally would be operating a shop there next to the car parking, if the canyon was open. She informed me that many big rocks have fallen into the canyon, it is considered dangerous at the moment thus will remain closed. They will have it fixed and ready for the start of the season next year 2019.
The only thing you can do is walk to the bridge close to the blocked entrance and get a glimpse of the canyon below. Judging by the number of cars which came, realized the canyon is closed and left, I believe that most of the people are unaware that the canyon is still closed.
Patience until next year when it will reopen!
Yufugawa canyon car parking and entrance is around 10 km northwest of Mukainoharu Station on the JR Kyudai Line, around 15 minutes by taxi.