@Spendo02:
From what I understand, as long as Japan has to roll a die for a unit, it can use any amount of Kamikaze it has remaining.
Through Alpha2, Japan does not have to have any units defending to use kamikazes.
 I’m presuming this would include a Trn with no other ships present as the rule is meant to save time rolling an inevitable, and not avoid combat entirely?
No. If there is an enemy conducting combat in a kamikaze zone (amphibious or naval), Japan can use any number of kamikazes. Kamikazes target specific ships, but only surface warships (anything but transports or subs). This is not predicated on the presence of any Japanese units, transports or otherwise. Pretty sure I have this right - I don’t have the rulebook with me now to confirm.