Maru Gata (round shape) tsuba. Design of Mitsu Boshi (三ツ星), three stars, in a Misumi or Sankaku (三角), triangle, in Sukashi (透), opening. Maru Mimi round border, without Kozuka and Kogai Ana.

• Height: 77 mm
• Width: 77 mm
• Thickness: 4.5 mm
• Weight: 100 g

This Tsuba comes from a Tsuba Yagyu Owari and is now the symbol of the Minosaka society.

Yagyū Ren ya Toshikane (柳生連也厳包, 1625-1694), 5^th Sōke of the Owari Brance of the Yagyū school, was in the service of the Daimyō Tokugawa Yoshinao who governed the Province of Owari.
Renya was a deserving combatant and recognized as such, He won 30 duels in the presence of Yoshinao without being touched once.
In order to perfect his martial practice, Ren'ya created 36 Tsuba Designs, the 36 Kasen-Tsuba, later called the Tsuba Yagyū.
The design of this Tsuba Mitsu Boshi Sankaku Sukashi (三ツ星三角透) is the most iconic of these Kasen-TsubaTsuba.

The 3 stars mean according to:

• • the "Three fundamental studies" (Sangaku, 三学) of Buddhism:
  • - Kaigaku (戒学, precepts),
  • - Jōgaku (定学, contemplation and meditation),
  • - Eigaku (慧学, wisdom).
• 
  • Three ways of learning, according to Ren'ya Yagyū, are essential for the advancement of the sword:
  • - Narai (習い, Learn),
  • - Keiko (稽古, Practice),
  • - Kufū (工夫, Dedication to Improvement).
• 
  • In the "Shōden-Shinkage-ryū" (正伝新陰流), Yagyū Toshinaga (柳生厳長), 20^th Sōke describes them as:
  • - Shin (心, Heart),
  • - Ken (剣, Sabre),
  • - Tai (体, Body).
  integrated into a circle, which in turn represents the desired ability to change technique at will and smoothly move from one movement to another.