change the language to japanese after registering. then copy-paste this link(game page): http://www.dmm.co.jp/netgame/social/...app_id=156462/
edit: alternatively, refer to http://harem-battle.club/others/927-...ide-overd.html
you don't need the force cookie hack I think, just take note that you have to click the japanese. everything must be in japanese, but you can use the screenshots to help you navigate.