is it cheaper?

is it cheaper if i was to just buy a phone or rent a phone if i was going to japan for a half year to a year? and if so what are some sits that are good for rentals or buying phones in japan?

I think it'll be cheaper if you bought a cell phone with a monthly plan, rather than renting one. You have to provide some kind of proof that you're living in Japan legally. I was there for only a month so I ended up getting a pre-paid phone from AU (Cellphone Company). They were charging me $1/minute for outgoing calls (any calls you make). If you receive any calls, it's free. Unfortunately, you need some proof of residency to even buy a pre-paid phone. Luckily, my friend who lives there, went with me to buy one. Here are some links of cellphone companies in Japan:

Softbank
http://mb.softbank.jp/mb/en/

NTT Docomo
http://www.nttdocomo.co.jp/english/

KDDI AU
http://www.au.kddi.com/english/

Hope this helps! As far as I know, KDDI AU was the only company that sold pre-paid cell phones...when I was up there in August. Other companies may be selling them now. Aloha!