I used to live in Japan for a brief period of time and would strongly recommend not moving to Japan.
Yes, the girls, the AV and the entertainment is fun, but that is such a small portion of life there. I found that I had little time or money to do any of the fun stuff. So basically, I was stuck at home, watching God awful television and eating Doritos since that was about the only edible thing I could find.
Having the money and time to do all of the fun stuff in Japan is rough. I don't know many foreigners there that don't have more than one job and aren't working nights or weekends or both. I knew one person who worked FIVE different jobs. The average salary for a foreigner is around 250,000 yen or less than $2,500 a month with one job. Take out your $1,000+ for everything each month and it's not alot. AV is quite expensive as is doing anything there.
Some other things you should consider:
- Japanese people are busy. I know a bunch of people who work 6 days a week and I even know some who work 7. Sure, you might be able to get a date with a girl in theory, but when is she going to be able to meet you anyway? If you live on different train lines then her or in a different city, it will be even harder to meet up with the girl. I've been told - "I'm free next month" more than once.
- Japanese people for the most part suck. They are nice on the surface but they all got some serious issues going on.
- Travelling in Japan is always a pain. You have to walk to the station, wait for the train(and the connection if you need to), get grinded on by 5 or 6 random dudes in the train, then walk to where you are going. The trains shut off around 11 and midnight so you need to get out of places at certain times just to plan your escape. If you are working until 7PM like most people, that doesn't leave much time.
- Doing anything in Japan is a hassle. There's so many stupid rules about everything and it gets doubled if you are a foreigner. There has been atleast 3 or 4 times when I had to practically beg a place to take my money and still didn't get the items. I took an item to a register once and the worker just stared at me.
- Japan is super racist. All the staring, the same stupid questions and conversations and not being able to do some things becaue you aren't Japanese gets old so fast.
- The heat really sucks. You have to walk everywhere and most places inside are even worse than the weather outside which makes for an uncomfortable atmosphere. It's not fun carrying a hand towel all the time just to cool off.
If you must be in Japan, I highly recommend either visiting every few months or saving up and renting a room for a month there through a short term stay place. Then you can enjoy the fun and stay away from the rest. Otherwise, make your money at home, enjoy having money, get a car and work from there. Remember, there are very few foreigners who stay in Japan by choice after 2-3 years.