How can I decide my job in my future?

I'm studying French language in university in France and will complete my study in some years. I will study something else such as economic or philosophy etc. I'm native Japanese speaker and speak French and English. I like making plans in general and easily get bored. I can't really do "same thing everyday" jobs.

Is there any good jobs I should try or advice?

With your versatility in foreign language, you might be a great public relations or foreign relations representative for some big corporation. You might also want to work in something diplomatic that would allow you to use your language skills. Or you might be able to work for a publishing company translating materials from their original language into other languages. You might also want to consider teaching. Your skill with languages would be very useful in education. Or you could work in the travel industry. Wow, there's a lot of options. You're wise to be considering your future now, because you may think of additional courses you would want to take to help prepare you for whatever you choose. Contact businesses that sound interesting to you and ask what is involved in these positions and if there are more classes they would want you to have in order to consider you for employment in their business.

I knew someone who was Chinese and specialized in French. He turned down a job offer in France because it wasn't what he was looking for but having nothing else to do, went back to China and regretted it forever more. I recommend using what you know. Stay in France and build a career over there.

Interpreters are highly paid jobs and are in great demand. Polish your three language skills. Try to look for a job with the UN or some international organization like that.