[gambatte]

Yeah, I forgot about the possibility of MAC filtering (each device has a unique MAC address and the network administrator can specify which device can connect; another way of access control other than encryption). Pretty smart school, e.g. they don't want ppl surfing while in class. Ask around and see if other ppl can connect WIFI. Looks like you probably will have to opt for a data plan if you can't see an unlocked residential SSID.