Doom in Japan

Doom is known in Japan as ドゥーム( literally transliterated as Douumu, but understood as 『DOOM』). Official ports of Doom were released in under license from id Software by publisher  and distributor. This included versions of the PC Doom, Doom II, and Doom95, as well as multiple console versions in their Japanese releases.

PC-98
Ports of Doom to the  architecture were programmed by Infinity Co., Ltd. Though based on  processors like the IBM PC, the NEC PC-98 series featured a custom bus and different video hardware which made it binary incompatible with most PC software. Versions of the Doom games for this architecture were released on 5.25" and 3.5" as well as on.

Minimum system requirements

 * PC-9801/Fellow, PC-9821/Mate/Multi, or Epson PC-386/486 clone system
 * i386SX processor or later
 * 3.3 or later
 * SoundBlaster 16 or onboard for sound effects; MPU-PC98 MIDI or onboard / for music
 * Most VGA-or-higher equivalent PC-98 graphics adaptors are supported

DOS/V
Equivalent releases of all games were made for the standard IBM PC architecture, with minor tweaks for the version of  with full Japanese language support. Unlike the PC-98, ordinary PC software could execute under DOS/V on standard hardware without modification.

3D Alien Busters
At least one release by Imagineer in their DOS/V Series 6 was uniquely entitled DOOM 3D Alien Busters (ドゥーム), or 3D Alien Busters DOOM, depending on the context.

Windows 95
A double-disc release of Doom II along with Doom95 was also coordinated by Imagineer, containing versions for both the PC-98 and standard PC on each disc. This release touts compatibility with the Imagineer PCPad controller, and like some American releases, it includes an offer for free time on the DWANGO network, which had recently expanded its franchise territory into Japan.