For the briefest split second he looks like he's been caught out. He doesn't have an answer for that, aside from the truth that he was trying to get away from one of the weird memory hallucinations that have been plaguing him recently and was distracted enough to not notice Eiji's presence until he was much too close. He's not going to admit that.

"Tch." When in doubt, annoyance. "Nothing to do with you."