[GTJ]

Why would you want that kind of lifestyle for yourself, anyway? Nyororin and Firebird covered all the other informational bases so all I have to say is: Japan is not Mecca. It sounds like youre underlying logic might be, "I don't care what I have to do or suffer through as long as I'm in Japan". Truth is, you'd better care, cuz it's not easy even if you're a highly qualified individual with credentials and certifications out the ass. Oh, and unless your Japanese is top notch (I'm talking a solid, working command of sonkeigo and kenjyougo), forget about jobs having to do with dealing with Japanese customers like that convenience store job you mentioned.

With anything involving immigration, keep this in mind:

Their first priority is to protect the country's interests. That usually means keeping the money and jobs for the natives. Therefore, they won't let you in on anything less than a 90 day tourist pass if you don't have a really good reason for it, like you'd be doing something only a foreigner can do (teach English), for example. Any schmuck can work a stock room, and as Nyororin said, for cheaper than you, as the visa is an extra liability.

My advice? Think about going to Japan. Don't think too hard, but set goals for yourself. In the meantime? Finish college. You've got a long, long way to go and a lot can happen in three years.