Hiro Nakamura (Masi Oka) uses these swords during Season 1 and Season 2 of Heroes.
These are Hiro’s screen used Takezo Kensei prop sword set from Seasons 1 & 2, multiple episodes. One,Takezo Kensei sword that measures 40.5 inches long and a second, bonus, plastic sword that measures 23.5 inches.
The larger sword is a katana style sword and has a metal blade (appears aluminum), a hard plastic handle wrapped in decorative straps, and the iconic Helix logo. There is not sheath or leather shoulder strap included with this item. The smaller plastic is in distressed condition and has a broken handle. Both items are described as being used during production.