As someone studying this subject, I'm telling you it won't happen. Are you fluent in Japanese? Have you ever visted Japan? Are you extremely talented and/or a genius? If the answer to these is no, then either give up or get fluent.
This is not about why
you should get the job. This is about what
you have to offer Japan.
If you want to be a translator or work in localisation, these are the only jobs you are likely to get in a Japanese game studio. Forget about being a developer.
Also, you can't just become a game developer in any country, at all, ever, unless you start your own company.
To be a game developer, you need to have a specialistion in one field, and work your way to the top of the company. For example, get a degree in animation, become a junior animator, then move up the ranks to senior, and then maybe one day you'll get some sort of input in the idea development and if you are good enough, a game developer.
Nobody
ever walks into a job as a game developer.
My advice to you?
For Japan:
-Become fluent in Japanese
-Become a Genius
(lol)
-Change your mind from developer to translator. You have much more chance. (Though usually translators work in their own country.)
For Game Developing anywhere:
-Get a degree in something specific. (Concept Art = Fine art degree, Animation = Animation degree, Scriptwriter = English degree, Programming = Computer Science degree [others are available])
-Develop an outstanding portfolio
-Get a job, work your way up the company over a period of years
TADAAA.
EDIT: Jobs titled as 'game developer' will usually be for small indie studios who are looking for someone with a wide range of skills, not someone who will just reel off ideas.