He flew Nakajima B5N torpedo bomber from the carrier Sōryū during the Attack on Pearl Harbor, the Indian Ocean Raid and the Battle of Midway.

[1] He was shot down and lost his right hand during the Solomon Islands Campaign while flying from the carrier Jun'yō, but survived the crash and was eventually evacuated to Japan.

During one of the September missions near Jiujiang, Mori experienced an engine failure in the new aircraft and was forced to land in a nearby field controlled by the Imperial Japanese Army (IJA).

In November, while flying a mission from Hankou, his B5N ran out of fuel due to a problem and he again was forced to land in a field near the Yangtze River.

As his division of Nakajima B5N torpedo bombers reached the harbor they lined up to attack the United States Navy (USN) battleship row.

[1] Petty Officer Mori was not directly involved in the Attack on Darwin since he was assigned to patrol duty in the vicinity of INJ carriers.

[3][2] Infuriated about it, he considered dropping his remaining bombs on their position, however, he decided not to risk running out of fuel and returned to the IJN fleet instead.

On the way to the atoll, they were intercepted by a large group of Midway-based Marine fighters (six Grumman F4F Wildcats and 20 Brewster F2A Buffalos) led by Major Floyd B.

However, before the preparation could be finished, Sōryū was hit and set ablaze by three bombs dropped by dive bombers of Yorktown led by Lieutenant Commander Max Leslie.

[4][2] After the Battle of Midway, Petty Officer Mori was transferred to the new carrier Jun'yō, which sailed from Japan to Guadalcanal in early October 1942.

On 16 October, He participated in the hastily organized and ill-fated air strike to attack the enemy position around Lunga Point on Guadalcanal.

As they approached Lunga Point, Itō broke off the bombing run of the entire Jun'yō group in order to make another attempt, which infuriated Mori.

Petty Officer Mori lost his right hand and was forced to ditch his bomber in the water near Cape Esperance, which was held by IJA.