Naga Maru Gara Tsuba (oval). Namako Sukashi 海 鼠 透, Sea Cucumber or Holothurian openings.

• Material: Iron, smoked black finish
• Dimensions: 74 mm x 69.5 mm x 4.5 mm
• Weight: 90 g

Namako 海鼠, or Sea Cucumber, is composed of the Kanji 'sea/ocean' 海 and 'mouse/rat' 鼠 because it resembles a rat crawling on the bottom of the sea. It is a delicate and fine food served for special occasions since ancient times. It is also used in medicine.
Namako is mentioned in a legend of the Kojiki, a collection of myths dating from the 8th century. It is mentioned as a dish of the Imperial court in the Engishiki, a collection of laws and regulations dating from 927. It has also been the subject of thousands of Haiku, in particular, because of its slimy touch, it is very difficult to catch.
Namako has become the mascot of the Japanese navy because it does not run away, does not hide, and has a thick skin protecting it from enemies.

This is a Tsuba design that is found in the oldest productions of the Muromachi period.
There are many similar examples of the Heain-Jo 平安城 school, with inlaid brass edging. This school was located in the old Yamashiro province, in Heian-Kyo 平安京, the old name of Kyoto. This school produced guards for the mounts of the nobles of the court during the Muromachi period, from 1390.