https://bugs.winehq.org/show_bug.cgi?id=49052
--- Comment #7 from Fabian Maurer dark.shadow4@web.de --- The game must be downloaded over their installer (http://dl-gameplayer.dmm.com/admin/win/installer/DMMGamePlayerSetup.exe)
I got the game itself from (NFSW) https://dlsoft.dmm.co.jp/en/detail/akbs_0100/ with my credit card, though it's a bit of pain to navigate since it's all Japanese. Not sure if I can make instructions to navigate that, but of course I could try to help. Otherwise, as noted, I could borrow my account which has everything already setup, you'd only need an activation code that's sent to my mail. Either way, feel free to send me a mail for details.
maybe some exact install instructions to avoid spending time for bypassing unrelated problems.
Install instructions I could provide. Though, as said, the client only works in a VM. You can copy the game out and it should give a message that "The game is not installed properly" because of the DRM. But it doesn't even get that far.