Odachi (Nodachi) – Japanese Curved Sword
Odachi (or Nodachi) is a long curved sword used in Japanese martial arts such as Ninjutsu and Bujutsu. Odachi/Nodachi also known as the O Tachi (literally Great Sword) are longer and heavier than a typical Katana. It was best suited to attack mounted warriors though the traditional slashes and thrusts.
There are also many examples of ceremonial Odachi (some of them of tremendous size) that were made purely for show (typically in Shinto shrines and temples) that were never intended to be used as actual weapons.