In 1189, one of the greatest Japanese warrior, not a samurai exactly, dead in an amazing way, which became a legend. His name is Benkei. He was a man of great strength and loyalty. This guy was a retainer of a general of the samurai clan of Japan, Yoshitsune, who is also considered one of the most popular and famous samurai fighters in the history of Japan as a skilled virtuous warrior and as a tragic hero.
Making a long historical story short, Yoshitsune’s elder brother turned against him and sent hundreds of soldiers to kill Yoshitsune. As Yoshitsune retired to the small annex of the castle to commit ritual suicide on his own, Benkei fought in front of the main gate to protect Yoshitsune. Long after the battle, the soldiers noticed that the arrow-riddled, wound-covered Benkei, who had killed tens or hundreds of fully trained soldiers, was standing still but dead in the standing position. This is known as the “Standing Death of Benkei,” which shows his real loyalty and considered as “That’s the Man!” kind of death in Japan.
Of course, it is just a legend. However according to scientists, it can be possible. When a human dies, rigor mortis occurs, in which chemical changes in the muscles cause the body of the corpse to become stiff and difficult to move. In humans, it usually takes about 3 to 4 hours to start, reaches maximum stiffness after 7 to 12 hours, and gradually dissipates until approximately 48 to 60 hours after death. However when a person died during or right after intense exercise, it is not the case. Rigor mortis is caused by depletion of oxygen used in the making of ATP. During intense exercise, for example fighting with hundreds of samurais, a body is already in depletion of oxygen and ATP; therefore rigor mortis commences after much shorter time. In addition, deep wound and/or arrows stuck in a body can also make muscle stiff hence preventing a dead body to bend.
Having said that, it is unlikely a dead body stands still and most people do not actually believe the “Standing Death of Benkei” is true. However it is true that Benkei fought to protect his lord till him dead, and Benkei’s loyalty and honour have passed down from generation to generation.