The Norimitsu Odachi is a huge sword from Japan. It is so large, in fact, that it was said to have been wielded by a giant. Apart from the basic knowledge of it having been forged in the 15th century AD, measuring 3.77 meters (12.37 ft.) in length, and weighing as much as 14.5 kg (31.97 lbs.), this impressive sword is shrouded in mystery.