https://bugs.winehq.org/show_bug.cgi?id=48174
--- Comment #4 from Rafał Mużyło galtgendo@o2.pl ---
Note that a Japanese locale is necessary for these characters to be representable in ANSI encoding.
Note that most Japanese programs I've encountered (which isn't all that high a number actually) need to be run in the Japanese locale to work properly. Some plain refuse to work at all otherwise.
OK, keeping the sarcasm in check from this point on.
As far I understand the Microsoft docs, as StringToHGlobalAnsi doesn't take an encoding as a parameter, it works with CP_ACP. Meaning the String object it's being fed is already wrong (unless, that is, mono implemented that call wrong). I didn't mention it before here (I did on the chat), but the mangled title is a result of the utf8 string with the expected title being converted as if it was in CP932 encoding. I'd suspect a MultiByteToWideChar call at some point, but didn't see it in WINEDEBUG, so an equivalent might be happening somewhere in mono code.
So, comment 3 seems to only move the goalposts - by that call, thing is (most likely) already broken.