All phone companies will auto-extend you, if you don't go in and stop them within that period. Last time with Softbank, I missed by less than a day (it was something like 5 hours), but I caused a small ruckus, and asked to speak to the manager - who after a few minutes allowed that it would be unfair to make me renew. We left, and went to AU.
I'm pretty sure of one thing with regards to mobile phone companies here in Japan: they're ALL crooks.
http://with-malice.com/ - The half-crazed ramblings of a Lakers fanatic in Japan