I always say this to people and they always say “It's too expensive”.
No It's not. In my work have been lucky enough to travel to every single prefecture in Japan, as well as many countries abroad. I can tell you it is nearly always cheaper to travel out of Japan than it is in Japan!
A little while ago I travelled from Osaka to Sapporo, and for the same price I could have travelled to America and back ? twice!
The key is to find cheap tickets, there are many around. Have a look in the English Language papers in Japan, there are always lots of advertisements in there.
If you can, try and avoid package tours. With a package tour, you are inside a kind of bubble where you only have to speak Japanese, which means you are not speaking English.
What you should do is to just book a flight and hotel. “That's too scary”, you may say. But don't worry, That's what makes it fun.
Don't believe all you hear about foreign countries being dangerous, they're not.For example, in England all we hear about Japan is of earthquakes, tsunamis, typhoons and volcanoes.
If you only read the English news you'd think Japan was very, very dangerous place. But It's not like that really, is it? And It's the same with other countries. Just like in Japan, as long as you don't do anything too stupid, you'll be fine.
Enjoy the World, because It's a fantastic place. Plus now you have the confidence and English skills to enjoy it even more.