Looking for hiking groups around Tokyo and nearby regions

You can try this website. https://www.meetup.com/cities/jp/tokyo/outdoors-adventure/?country=jp&zipstatecity=tokyo&category_names=outdoors-adventure&state=&radius=25

Hi Jane, thanks for replying.

I am an active member of Meetup for several years. Meetup was one of the first places I checked, even changed my location to Tokyo so as to get better event updates :). So far, not many events during my time in Tokyo but did find a paragliding event that I will likely do. It falls immediately on the next day after my return from Mt. Fuji. I think that is doable.