ジャルート環礁
Arima was born in Ijuin village (present day Hioki city), Kagoshima prefecture. He graduated from the 43rd class of the Imperial Japanese Naval Academy in 1915. He was ranked 33rd in a class of 96 cadets. As a midshipman, he was assigned to the cruiser on its 1915 long distance navigational training voyage from Sasebo to Chemulpo, Dairen, Chinkai, Maizuru and Toba. He stayed with "Iwate" on its cruise the following year to Hong Kong, Singapore, Fremantle, Melbourne, Sydney, Wellington, Auckland, Jaluit Atoll, Ponape, and Truk. On his return, he was commissioned as an ensign assigned to the battleship .