I jumped there in 2006. The Tokyo Skydiving club is located at the Honda Airport about 2-3 hours outside of Tokyo (train and bus). One ticket (credit cards where not accepted, cash only) was about 60$. They had a Cessna 208 at that time which could carry 8 skydivers only, because seats had to be installed for some reason. There were tandem instructors from Europe, so you could speak english and also the national 4-way teams (which usually train in the US) spoke english. You had to apply for a temporary japanese parachute associations membership in advance (50$). It was in 2006, I had no smartphone and it was quite hard to make the way back to Tokyo, because in that area all bus timetables, etc. were in japanese language only, and most of the locals do not speak english at all. I was there because a friend got married to a japanese girl, and had let him do the paperwork in advance. If you need any help, let me know, I could ask my japanese speaking friend to call the dropzone for details.