In ancient times the building in which a sword was made, called a forge, was regarded as a holy place. The walls adorned with images of gods, like the god of sword-making, Kaneyama-Hiko-No-Kami, and the Goddess of the sun, Amaterasu depicted to the left. Swordsmiths were often granted nobility and social status as they were perceived to be granted the spirit of the gods. There was intense preparation before a sword could be crafted that included long prayer and the purification and fasting of the swordsmith. The completion of a sword was celebrated in the ceremony, " The signing of the sword" which adorned the smith in priest-like robes and was, "considered no less miraculous than the birth of a child" (Mumford 1905). The Shinto faith says that a sword is the soul of the samurai. So the belief is that those that would die with the sword in hand would be spared of evil-reincarnation, and that with the sword nothing should be feared in this life or the next. 

Swords not only held the soul of the samurai and godly spirits it is said to hold the spirit of its maker. In the case Muramasa from the home page, his swords were "bloodthirsty" and had evil spirits. People said to have Muramasa swords often committed crimes and even lead to multiple accounts of suicide as owners battled between honor and the spirit of the sword. 

William Bascom identifies four main functions of folklore; the function most pertinent to Japanese swordsmithing is maintaining cultural identity (Sims & Stephens 2011). Beyond the historical significance of Japanese swords in their place in war and politics (see The History) and the lineage of both the craft of smithing and the swords themselves as heirlooms, swords are even further a reflection of Japanese culture. The blade is said to be the narrow path to justice (Mumford 1905). The sword represents obedience not just to law and order that was enforced with the sword by the Tokugawa Shogunate but obedience to honor itself. This is evident in the importance of these heirlooms and the modern tradition of emulating the work of ancient smiths. This has lead to a Japanese culture focused on honor and discipline to the values of their land and history with the sword as its backbone. The obvious connections to Japanese history, politics, family, land and region, mythology, animology, and spirituality are all embodied in the making of a sword represented through not only the process but the artistry and decoration of the sword and its ornaments.