Honoring the first prototype, these first twelve production models are finished in the original matte titanium and black colors.  

Number 46 is the second in this group and is named after Isogai Masahira. He was 25 years old when the head of the enemy, Kira, was taken off in revenge of his master. He too was one of the loyal subjects of Asano. - Forty Seven Ronin 1893