The game connects to the Mobage server when it boots up, and unless I log into my Japanese account on the App Store, it won't let me progress. I've only played the iPad version, so I can't speak for Android, I'm afraid!
(as far as i can tell, the Mobage connection is just to display ads on the title screen and to facilitate the microtransactions, which is a crummy way of locking people out)

I also made a quick page to list the characters - the whole page is just a placeholder and the translations are mighty sloppy, but any help is appreciated. I'd love to know who the heck 佐古田 幸雄（48） is supposed to be!