My iPhone is from Japan and I want to activate it here in the Philippines because I'm living here. I have lost the original SIM from Softbank and replaced it with a new SIM card from Globe. How can I use the SIM card from Globe?

You cannot. The iPhone is locked to Softbank, and only they can unlock it. Problem is that Softbank will NOT unlock the phone, as they do not offer iPhone unlocking.

Buy an iPhone in the Phillipines.

PS Before you go on a rant at Apple, be aware that Apple does NOT unlock phones and they do not set unlocking policies. The carriers (Softbank in this case) set the unlocking policy.