From Wikipedia:
Standard issue
SCK/Minebea 9mm Pistol
Minebea 9mm Machine Pistol
Howa Type 89 (120,030)
Howa Type 64 (230,000)
Type 06 rifle grenade
Sumitomo MINIMI 5.56mm Machine Gun (4656)
M24 Sniper Rifle
Howa Type 64 Sniper Rifle
NTK/Sumitomo Type 62 machine gun
NTK/Sumitomo Type 74 In-vehicle machine gun
Sumitomo M2 12.7mm Heavy Machine Gun
Howa Type 96 40mm Automatic Grenade Launcher
Howa 84RR
Nissan/IHI Aerospace 110mm LAM
Special forces
H&K USP(Only Japanese Special Forces Group.)
H&K MP7(Only Japanese Special Forces Group.)
M4 carbine (Only Japanese Special Forces Group.)
M203 grenade launcher (Only Japanese Special Forces Group.)
Also found this:
Firearm Type Calibre Service
Meiji Type 26 Revolver 9mm Meiji 1893–1945
Nambu Type 14 Semi-automatic 8mm Nambu 1915–1945
Nambu Type 94 Semi-automatic 8mm Nambu 1934–1961
Nambu Model 60 Revolver .38 Special 1961–Present
Minebea P9 Semi-automatic 9×19mm Parabellum 1985–present
Thank you - that’s an excellent answer.
Checking it out, I found that the SCK Minibea pistol is a SIG 225 9mm made under license by Minebea as the Minebea P9.