The Type 94 designation was given to this gun as it was accepted in the year 2594 of the Japanese calendar (1934).

[4] Japanese 90mm, 120mm, and 150mm mortars were labeled as "trench mortars" and were effectively controlled by Imperial Japanese Army artillery units instead of infantry units.

[5] Initially Japanese trench mortars where primarily developed as chemical-delivery weapons, but would mainly see service in conventional roles during the Greater East Asia War.

[7] By giving the Type 94 an especially heavy and stable mount and bipod, a massive shock absorber group, a powerful projectile, and a lengthy tube and heavy powder charge capacity for long range, Japanese designers intended the weapon to serve as a substitute field or artillery piece that could be hauled in pieces to remote locations, a useful attribute for an army short on transport as well as modern towed large-caliber field howitzers and artillery.

Japanese forces sometimes went to great lengths to transport these heavy mortars to remote jungle locations when preparing defensive works.