Imperial Japanese Naval Academy
In September 1876, Tomioka enrolled in the 5th class of the Imperial Japanese Naval Academy and graduated at the top of his class. In 1878 he was sent as a cadet to serve on the Royal Navy warship HMS "Audacious". After his return to Japan, he graduated from the Navy Staff College. During the First Sino-Japanese War, Tomioka served as executive officer on the cruiser . He subsequently served as captain of the dispatch ship , instructor at the Imperial Japanese Naval Academy, captain of the cruiser and of the battleship and director of the 1st Bureau of the Imperial Japanese Navy General Staff.