How to Improve Pronunciation
There are many books on pronunciation you can buy, but you do not need them. There are many resources available on the internet which will help you improve pronunciation.
The best resource is: http://www.uiowa.edu/~acadtech/phonetics/english/english.html
This has the IPA symbols for all the English speech sounds. You should learn the speech sounds as we see them in dictionaries all the time, for example:
Now you can study the IPA Symbols, and slowly improve your pronunciation. At One Gengo, we have pronunciation exercises that will improve your speech. One important thing that Japanese should also do is tongue exercises, for example sticking your tongue out, putting your tongue on your teeth, and pushing air out from your throat.
As all One Gengo`s English Language Speech Instructors are master degree graduates in Teaching English, you can be happy to know we are trained to teach you how to speak.
Improving your Pronunciation for Free: PDF: http://ow.ly/d/2YUn