Not as much as Imperial Japan would have you believe. A lot of samurai mythos are either from the long period of peace in the Edo Period, when samurai felt the need to prove how incredibly warrior-like they were at every opportunity (because there were no wars going on and they would look lame otherwise), or from the period of compensatory ultranationalism in the Japanese Empire, when they felt the need both to differentiate themselves from the European civilizations they had learned from, and to prove that they were, in some way, superior, in the same way that Europeans pretended they were superior.

When you read about, say, the Sengoku Jidai, the warring states period, samurai are always doing things that either of those influences would tell you shouldn’t happen - betraying their lords, running from battles, fighting dirty, surrendering, etc. But unlike European civilizations, there was less stigma associated to suicide - suicide could even be honorable, if done in the right way. That does give a bit more of a ‘do-or-die’ vibe to outmatched forces.