[Aga-chan]

If it wasn't for those intro lines, it wouldn't sound like boys/girls things at all. It seems more like "Give yourself to the moment, don't be afraid, even if you regret it, it's meaningless talk". I think the "beat" might not literary be a "beat". Maybe she took music and dancing as a symbol to talk about life. So "beat" may be thoughts, emotions, ideas that you have in mind, but are afraid to follow. It's seems like saying "Don't be afraid to live", "Don't be afraid to live the way you want".
And why is -tachi added to boys/girls? lol Wouldn't boy/girl-tachi make more sense?

To the actual song (I have only listened to it once, though): The arrangement is really cool. I still think the intro lyrics are kinda ridiculous, so that takes some points off, but other than that a cool track.