34, was an Imperial Japanese Navy Kaichū-Type submarine of the Kaichū III subclass.

The submarines of the Kaichu III sub-class were a slightly improved version of the preceding Kaichu II subclass, the man difference being an increase in diving depth from 30 to 45.7 meters (98 to 150 ft).

For surface running, the submarines were powered by two 1,450-brake-horsepower (1,081 kW) Sulzer Mark II diesel engines, each driving one propeller shaft.

They were also armed with a single 76.2 mm (3.00 in) deck gun mounted aft of the conning tower.

[2] On 3 March 1923, an explosion attributed to a build-up of hydrogen gas occurred aboard Submarine No.