The Sword of Hattanzo, was created by The Drifter.
This blade was created by a young sword-smith, who considered it his masterpiece upon its completion. His skills as a smith and swordsman soon attracted the attention of a duelist, who challenged the smith to a duel. They fought fiercely but the Duelist's skills were superior and he defeated the smith and took his sword from him .
For years, the Sword of Hattanzo stayed in the Duelist's ownership, as he used it to duel otherswordsmen and claim their swords, including the Sword of Omens which he claimed from Lion-O. Lion-O, with the help of the Drifter, challenged the Duelist to a rematch and won.
The Sword of Hattanzo was returned to its rightful master, and the other swords the Duelist had taken the Drifter kept so he could personally return them to their rightful owners.
The Sword of Hattanzo seems like an ordinary sword other than its quality craftsmanship and near-indestructability. The Drifter states it took him years to make the sword into the revered weapon it is today, and it must be of true value as it attracted the attention of the infamous swordsman, the Duelist.
The swords name most likey comes from the name of the sword smith 'Hattori Hanzō' from the 'Kill Bill' films, who, much like 'The Drifter', had not made a sword in years until meeting the main character.