[Anon doesn't seem especially startled that Natsuno's stolen the lead with that burst of speed -- the window is small enough that only one of them can squeeze through at a time, and even then it's enough to abuse the frame at least a little because they're both teenage boys and these windows were distinctly not meant to be used as entrances or exits.

(Too bad, because Anon is Anon and abusing windows has become his new pasttime.]

He just gives a laugh that sounds like it's slipped out in the midst of everything and pelts after him, not even bothering to shut the window. Natsuno's fast enough that there isn't quite the time to do that, even, and it adds a little spring to Anon's steps as he gives chase.

In terms of speed, really, they're evenly matched. Anon arrives a half-step behind and lets out a brief whoop at the flip -- but there's a reason he's lagging, and that's made apparent when he lowers his posture right smack in the middle of his sprint and goes straight in for a bodyslam to greet Natsuno coming down from showing off. There ain't any starting signals in this particular game.]