A little selection of my favorites in Japan
The Hida ridge traverse from Nishihodaka to Okuhodaka is a thrilling expert level hike which will require upper body strength for free climbing with your hands and chains.
Hakubayari Onsen to Karamatsu is a difficult 2 day traverse on the Hakuba ridgeline. On day 1 you get to soak in the amazing Hakubayari onsen.
Osugidani valley is an advanced in-and-out hike in Mie. It's one of Japans top 3 most beautiful valleys and accessible form spring to fall.