pkk234: Yea i'm down for em too.
I think Japanese companies have negative attitude towards DRM-Free though.
Not all for sure but many does. I'm not even sure they know it exist.
To start, the PC gaming market is almost non-existent in Japan, so devs and gaming companies focus entirely on console gaming (esp. handheld ones that are quite popular). You need first to make PC ports, which are outsourced even by large (international) companies. You also have to translate them.
Nihon Falcom, due to their history, allows their games to be drm-free, but its mostly the exception to the rule.
However, there's better chance with the japan indie scene and VN ones, but you can forget triple A games on GoG. I don't even think something like the non-far mode port of Nier Automata would even pass QC check on GoG !
Oh and by the way, Sakura's series are not japanese games, Winged Cloud is an english-spoken amateur group.