I reject this Tir logic: how could Kazuki have possibly hurt himself in a six-step walk to the bathroom that he himself witnessed? Use your head, Tenkai.

Kazuki, however, was trying his absolute best to discover powers of invisibility that he had previously never been aware of, or perhaps convince the floor below him to swallow him up whole.

The world had a funny way of not doing that when you wanted it to, though.