I firmly believe you can find a job within 1 month as soon as you start to look seriously. So start to tidy up things in the UK and get ready for such a move.
Hiroshima is also a nice area. Close to 1 of the 3 wonders of Japan -
Miyajima! You can also see the site of the Atomic blast during WWII and visit the museum. Though, my favourite part of Japan is Kobe. Mountains on one side and the Pacific Ocean on the other. It's also still a very thriving place.