 She was launched on 24 November 1939 with Shibata Genichi as Chief Equipping Officer, and Commander Shibata as Commanding Officer.She was then assigned to Rear Admiral Sato Tsutomu's "SubRon 1" Division, along with and .On 9 December 1941 "I-6" reported sighting a , as well as two cruisers, off Oahu.