Lieutenant Arima frequently attacked the supply shipping on Yangtze west of Yichang, which was particularly challenging for dive bombing as the Gorges can have more than 1000 meters cliffs on both sides.

In August, he was reassigned to Suzuka Air Group in Mie Prefecture, where he served as an instructor when Empire of Japan entered the war with United States of America.

The USN Combat Air Patrol (CAP) of Grumman F4F Wildcat fighters intercepted the formation of dive bombers, however, Arima's division managed to escape into cumulonimbus clouds and approached the carrier Enterprise unharmed.

His 250 kilogram semi-AP bomb penetrated the starboard forward corner of her number 3 elevator aft and sliced through to the third deck before detonating in the chief's quarters.

After the attack, Arima remained north-west of the burning Enterprise to wait for the friendly Zero fighters in order to lead them back to the Japanese carriers.

[1][2][4][5] In late October 1942, Shōkaku was again dispatched to the Solomon Islands to support the Imperial Japanese Army ground assault on Henderson Field on Guadalcanal.

As a simultaneous USN strike damaged the flight deck of Shōkaku, leaving her unable to launch or recover aircraft, Arima's D3A landed on Zuikaku.

[1][2][4][6] After the Battle of the Santa Cruz Islands, Lieutenant Arima was transferred to Usa Air Group in Ōita Prefecture on Kyushu and served as an instructor (together with his pilot Petty Officer Furuta).