It was almost impossible to get Japan to surrender in WWII. In the end, the Americans had to resort to nuclear bombardment. And in individual battles like on Okinawa and Iwo Jima, they often fought to the last man.
Was Japan always like this, though? If they faced a serious threat of invasion in, say, a wanked-up version of the Russo-Japanese War, would the Japanese be just as hard-core? If forced into a corner, would they be willing to sue for peace?