[Cutting a knot that won't open isn't that extreme, is it? This young man is so confusing...
BUT!]

Forgive me. Yes, an introduction might put you at ease. [He draws himself up and nods his head in a slight bow, hoping his smile is reassuring.]

I am called Tonbokiri, one of the Three Great Spears of Japan. It is a pleasure to make your acquaintance.