Essentially it says your account has been banned due to breach of the ToS, and lists a few common examples. They released an announcement saying they banned several accounts for something regarding the Casino - guessing it was related to this...?
You'll need to contact their customer support for more information. Do you speak much/any Japanese?
Not sure if any of the mods still support this community, but they should be aware that the forums are infested with bots and that their forum needs to be upgraded.