In order to get a student visa, you have to show that you have the funds (or that someone else who will pay has them) for all tuition. That could mean proving 2 million yen in the bank, and not on a sudden deposit.
If you get past this barrier and are accepted to a school, then yes, you will be able to experience some of what it's like to live here. It will be a student's life, of course, not one that a full-time working person has. You could apply for special permission to work, but it would be only PT, and some schools prohibit that for the first 3 months. They want to know you area really here to study.
Miss enough classes, and the school can withdraw its visa sponsorship, and you will have to start all over again. So, choose wisely and stick to it.