Sorry to interject randomly--I was reading what this roleplay was about when I came across this statement.
Ōdachi aren't the swords used by upper samurai men on horseback--that is the Tachi. Its a sword that has more curvature than a katana, and is always worn blade down. Tachi are only slightly longer than standard Katana and were more prestegious as they often belonged to officers. Their hilt is so that a grip can be maintained while slashing down at a foe while galloping. These were akin to Sabers.
Ōdachi (大太刀) (large/great sword) were very large, two handed weapons that had dramatic length and were used by foot soldiers. The blade was made so, so that it could cut the horses legs out from under it or cut the horse and and its rider in one cut. They were Dai, or great sword and were eith slung over shoulder, carried by hand--or in the case of upper nobility, carried by a servent like Sojio Sasaki--the man killed by Miyomoto Mushashi with a qoodden paddle shapped into a type of bokken.
Ōdachi were indeed hard to make, and they lost their appeal after the Siege of Osaka of 1615 between the Forces of the then Regent Toyotomi Hideyoshi and the would be Shogun Tokugawa Ieyasu. After the Tokugawa shogunate was established, there was a standard enforced, on how long swords should be.
Kendoka like myself, have learned Kenjutsu through use of bokken shapped like Ōdachi. The added weight builds the arms and upper torso--thus giving more power behind each swing and making your swings faster because standard Katana don't weigh as much.
There were several other weapons that Samurai used, dependent on their clan. The Yumi bow; the larger variant is called a daikyū it was tyipically used by foot soldiers or samurai, and hankyū which is a shorter variant used while mounted. The art of this weapon is called
kyūdo or
kyūdojin.
The Yari spear, was another typical samurai weapon. It was used in much the same way any spear functions, though not all Yari had straight points. Some hadded added blades to hook or ensnare. And dependent on the yari, it could reach nearly twenty feet in length.
The Naginata was a halberd, with a three foot curved blade. The wives of Samurai trained with the Naginata to protect the home and honor o the homestead while the male was away on his affairs.
Nagamaki were crafted much like a naginata, except instead of a polearm, it had an extended hilt. Every thing was crafted exactly like a naginata except the hilt.
You also have the kanabō. A thick wooden, or iron club with studs all over. It was meant to break the legs of horses or simply crush someone with bludgeoning force.
There were other armaments that samurai used--but I don't know what time frame this story is supposedly occuring.
Tachi:
Ōdachi :
Daikyū:
Hankyū:
Naginata:
Nagamaki:
Yari:
Kanabō:
