Sorry for the late answer, but well, at least here i am now.
So, as i spoke before for some RPGM games you may have to install the RTP since the game uses some assets that will be installed alongside it. That VL Gothic font for an instance is one of the files that get installed alongside the RTP for what i believe to be RPGM VX Ace.
Another reason for that kind of error may be that you do have installed the RTP package but since japanese games does use non-unicode characters it may be messing with the path to the files and generating an error. In that case you should use Locale Emulator or manually change the local of your computer so this way the game might be able to properly work.
I don't really like to put up links here but i believe it is for a good reason so i'll leave here the links to the
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and to the
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.
Also, i noticed sometimes that there are some differences between ocidental RTP's and Japanese ones, so if even with the Locale emulator and the RTP the game still throwing errors you might have look trying the RTP that the developer linked on the DLSite page of the game.
Hope i have helped.
EDIT: Forgot to say, but about the Locale Emulator, the version i usually use is the 2.4.1.0
