 During the US invasion of Saipan in June 1944 , Japanese troop ships attempting to reinforce the defenses were sunk by submarines . Shigenori Kami , chief of operations of the Navy Staff , volunteered to command Yamashiro to carry troops and equipment to Saipan . If the ship actually reached the island , he intended to deliberately beach the ship before it could be sunk and to use its artillery to defend the island . After Ryūnosuke Kusaka , Chief of Staff of the Combined Fleet , also volunteered to go , Prime Minister Hideki Tōjō approved the plan , known as Operation Y @-@ GO , but the operation was cancelled after the decisive defeat in the Battle of the Philippine Sea on 19 and 20 June . 
