"Alright." Ryoji won't follow her immediately, but he also can't let her get away. The logical response? Take the knife he always carries and cutting into his hand when she's not looking, bidding the blood that comes from it to follow her. He can look through it, if he needs to, and it can move as fast as he can so it should be able to keep up with her for the most part. Of course, that's probably something she can smell following her...