I'm having the same problem and a union member of mines encountered the same problem with the same ISP. I'm not sure if it's DMM or the ISPs doing it but somethings blocking access to DMM which is preventing the game from launching on nutaku as the game is hosted on DMM. You'll have to use a VPN so you can launch the game. This applies for any games that directly hosted by DMM. Both Kamihime and Dragon Providence for example.