If this is the sub sunk by the Ward, then the damage should be visible. If it's not there, then perhaps the Ward sank another sub with its depth charges.
The sub led four other Japanese midget submarines to Pearl Harbor to take part in the attack. The newly discovered sub was believed to be the one sunk by the destroyer USS Ward before the attack began. Wiltshire said the crew is certain that this sub was sunk by the Ward because of a bullet hole in the conning tower and because it still has both torpedoes. Three of the subs have been previously accounted for; the remaining sub had fired both of its weapons.
The damage, apparently, is visible. Strongly suggests that this wreck is the Ward's target. FWIW, I think the wrick should be raised and preserved for the historical artifact that it is. Human remains, if any, should be returned to Japan for burial.