You can never think too much about the rules. I posted a long comment asking questions about the rules on this video. ---> http://xhamster.com/movies/1460621/cock_hero.html
There is a lot of details left out on these videos. :)
So there was another post of this video on this site, presumably the original, and somebody asked who the neko chick with white hair during the end was. Can't seem to find the original video with that comment (I guess it was removed) so I'll just post it here. The girl from what I can tell is Black Hanekawa/Hanekawa Tsubasa from Nekomonogatari of the Monogatari series. Hope whoever posted that comment sees this ._.
I have a way of doing it that feels pretty accurate of how you're supposed to. If the arrows are spread apart you stroke your cock down when the arrow passes and up in between the next one so you can keep to the beat. So you'll pretty much be stroking down every beat and up on every off-beat.
As for the rapid arrow segments, those are simply up on one arrow, down on the next in rapid succession. My personal favorite parts. It's also best to let go of your cock during long pauses.