Why Japan? You should read this thread:
Graduate from college if you want to live in Japan.
I will be blunt, nobody will hire you and offer you sponsorship for a job visa, not unless you have some really exceptional skill that they really want. Especially in this economy.
Not just ANY job will give you access to an apartment, life in japan is not easy, and its very expensive. For a foreigner to get a job and to live there comfortably, you really need to be at least working in middle management of some sort or someone that is in some form of specialized profession
Your other option is to get married to Japanese. It was mentioned in other thread as well that Japanese are very realistic and practical, they look for security financially as well