I was watching this past Monday's episode and I realized that I can't remember what actually happened to Hiro's Kensei Sword... the last I remember it being in his possession was when he used it to attack Adam and Peter at Primatech.

Can someone remind me?

Not 100% on this, and I'll check the facts in a minute, but I think it's in Japan. I'm pretty sure he left it with Ando.


ETA
Looks like Hiro reclaimed it at the cemetery where he buried Adam, but it hasn't actually been seen since. (Although it was the Kensei Sword that F_Hiro used when F_Ando attacked him. And Hiro had been killed with it in Angela's vision of everybody dead.)

He also had his sword with him when he dug Adam out of the grave and went to that particular bar with him, I believe. Where I lose track of it is somewhere between then and when he has his memories erased in Africa by Arthur Petrelli. Hm...

I'll have to check it out, but I'm nearly positive he didn't have any sword with him at that time.

Yeah, it was a different sword he kabob'd Ando with.

Mmm, pretty sure the present time's Kensei sword wasn't seen since "Powerless." It's likely resting in Ando's office but it could have been transferred to Hiro's (formerly Kaito's) office off screen.

Its in my den! hahaha..

He had it with him in the finale of season 2. There were some problems because they showed the sword in Ando's hands when he found the notes in the handle and it was still broken in half. However, when he came back from ancient Japan he grabbed it off Ando's wall and it was fully repaired. The writer's said it was a prop or continuity error. He definitely took it with him when he went to fight Adam in Odessa at Primatech.