Nikolaevsk Incident [Niko Jiken]
Inscribed 'Nikolaevsk Dispatch Army, Mountain Artillery
Victorious Return Commemorative.'
The Nikolaevsk Incident [in Japanese this is called the Niko Jihen] happened in
1920.

During the Siberian Intervention (1918-22), 'the Japanese and White Russian
garrison at Nikolaevsk at the mouth of the Amur River surrendered to partisans.
The Japanese broke the surrender agreement to counterattack but were
defeated with heavy losses. The 136 remaining Japanese soldiers and some
350 Japanese settlers were taken prisoner.

In May 1920 the partisans withdrew when threatened by a Japanese relief force
after killing an estimated 700 Japanese prisoners and Russian
counterrevolutionaries. Those responsible were later sentenced to death by the
revolutionary government, but the Japanese demanded compensation,
occupying northern Sakahalin to enforce their demands.

Although Japan withdrew from Siberia in 1922, it was only in 1925, when formal
relations were resumed, that she withdrew, without compensation, from
Sakhalin.'
                                        from Hunter's Concise Dictionary of Modern Japanese History

I have seen few cups with an inscription referring to this incident. I imagine that
they were awarded to the relief force soldiers.

Read more about this incident here on Wikipedia:
NIKOLAEVSK.
'Nikolaevsk.' The Japanese reading is Niko.
Inscribed 'Nikolaevsk, Victorious Return Commemorative,
Asahigawa  27th Infantry, Sakurai.'