From: Tokyo Registered: 2007-02-06 Posts: 840 Website
As Bokusenou says, use an unarchiver. "Stuffit Expander" opens it on my Mac. You then get a folder containing seven fonts; just double-click on any of them and Font Book will ask if you want to install it. The 教科書 font is presumably the one titled "epkyouka.ttf".