Officer’s dress sword with ornate handle and mother-of-pearl inlaid scabbard. The blade is too rusted to pull out. Japan, Heian period, 12th century AD
About 80 years ago we polished a sword found from the ceiling of the treasure house of Kasuga Taisha (Nara City) and found out that it was the oldest Japanese sword made in the 12th century.
This was named so because its Tsuka ( handle ) has openwork with in the shape of tweezers ( kenuki ) .
This is an unsheathed sword used on a horse , became the original shape of Kenukigata-Tachi ( hair-tweezers-shaped Tachi ) that developed into Japanese swords.