User blog comment:Rtys8/Okay.....i'll have to aplogize a bit on some slight accuracy issues./@comment-16526045-20140611130615/@comment-1960111-20140615133842

I think we need more confirmation, or just leave it like that. As far as I know, there's no practical way to cut steel with pure human strength alone, even if the sword is great. Also, hardness and sharpness are kinda in different category. In my opinion, Kannagiri was a sword as thin as a piece of paper. It won't be very durable but the thin blade will allow it to cut through other objects at molecular level, hence the reason Misuzu can cut through Ira's armor.

Actually maybe that doesn't apply in a fantasy world like 11eyes but...I think I can trust the author to be at least that realistic.