What are the best bikepacking routes across japan? What kind of bicycle do you recommend for a 6 months bicycle bikepacking trip across japan? Gravel or Mountainbike? or another?

Hi I’ll bikepack across Japan for 6 months. What are the best routes? Please recommend me everything. You can also just drop blogs guides etc you found useful, I’m thankful for everything!!🙏🙏🙏

I’ll basically ride everywhere since i have so much time. What bicycle do you guys recommend me? are there people here who already did this bicycle trip and can recommend me a bicycle? I heard i should get a gravel or mountain bike