Most of the time, legendary swords are the stuff of video games and fantasy novels. However, the real-world has its fair share of mysterious blades, and one of the most famous, the Japanese samurai sword known as Honjo Masamune, is now lost somewhere in America. Here’s what we know about the world’s most sought after weapon:

The legends surrounding Honjo Masamune are mostly just that: legends. With that said, it’s impossible to know if the stories surrounding the blade, or its creator, are accurate. What we do know is that the sword was created by a man named Goro Masamune sometime in the mid-13th century. Masamune was one of the most well-known swordsmiths of his time and was able to make remarkably well-crafted swords out of rough materials using little technology.

Before we get into the sword, it’s important to discuss the legend that set Masamune apart from his peers. During his life, Masamune reportedly competed with another blacksmith named Sengo Muramasa. Both of these blacksmiths were masters of their craft and made swords for royalty and other wealthy individuals. So, in order to find out who was the best in all of the land, the two decided to test their swords by suspending them in a stream so that they would cut the fish and leaves that ran into it. Muramasa’s blade cut everything that it came in contact with while Masamune’s cut only leaves and twigs. Muramasa declared himself the victor because his sword was obviously the sharpest and most fierce.

However, a passing monk had stopped to watch the contest and proclaimed that Masamune’s blade was far superior because it only cut things that were deserving. This meant that Murasama’s blade was bloodthirsty and cruel, while Masamune’s was pure. From there on, Masamune’s reputation continued to grow until he was viewed as the best swordsmith in Japan because his blades were imbued with a magical, honorable essence. Though this story is cited often, some have pointed out that it couldn’t have happened because Masamune and Murasama weren’t alive at the same time, a fact that hasn’t stopped the story’s fame at all.

Though historians are aware of the existence of many of Masamune’s swords, many of them have been lost of the years. One of the most well-documented and looked after swords was the Honjo Masaume, named after one of the people who first wielded it, Honjo Shigenaga. After spending its early years in the care of Shigenaga, the sword was passed on, through battle, to the Tokugawa family where it was then passed down again and again throughout the generations all the way up until the World War II.

According to the legend, when Japan surrendered to the Allies at the end of World War II, Honjo Masamune belonged to Tokugawa Iemasu, President of the House of Peers. For some reason, the Allies demanded that all of the noble families turn over their sword collections. Needless to say, most families were upset about this and fought back. However, Iemasu wanted to set a good example and turned his collection over immediately.

This is where the story seems to differ dramatically because no one can agree on who exactly took Honjo Masamune from Iemasu. Some claim it was a man named Sgt. Coldy Bimore who likely took the sword home as a souvenir of war.

Despite some reports indicating the man’s name, he has never been found and, therefore, the whereabouts of the sword remain a mystery to modern scholars. It is generally agreed that some American soldier took the sword, which means that a random family in America may have one of Japan’s most famous swords laying in their basement or attic.

So, if you are reading this and your father or grandfather has some sort of samurai sword that he brought back from Japan, you may want to hurry it off to get it appraised, because you may have a priceless, semi-magical artifact in your possession.