[atheistwithfaith]

There is as good as no chance of you finding employment while there on a visitor visa, and even if you get a working holiday visa its very highly unlikely you will find work unless you are very fluent in Japanese and have obtained your degree (which I'm guessing you wont have by that time).

I would say your only option is hard graft in your holidays.

For accomodation, depending on where you are staying it can be quite pricey and 3 can be a bit of an awkward number of people. If you plan to stay in Tokyo I'd say you could find somewhere for about $500-700 a month for each person. I don't know much about homestays at all, but I would look into that - as long as you realise if you want 3 of you to stay then it would most likely be somewhere out in the countryside.

Long story short; you will not be able to find employment there, you are going to have to save up in your home country, you might be able to do a homestay.