You don't have to know Japanese, really. You get a nice preview of the location and schedule mechanics (going places drains the clock), and the conversation mechanic (you can talk about things like the weather with a girl). For some reason the cartesian graph does more than display whether the girl likes or hates what you did (I think the "phases of the moon" symbol next to a character name does that).
Then you get treated to the "battle" system, which is basically Dance Dance Revolution with your mouse button. You get to fight one of Touka's (the protagonist's name) classmates and then one of the girls in "combat" (just click when the arrow points up and don't click when the arrow points down).
If you translate it, or at least transliterate it, we can create a tag specifically for this particular doujin so we can find it more easily in the future.
I hope we find more stuff you enjoy in the future!
...-san, are you awake?Are you still sleeping? You're such a sleepyheadCome on, wake up, it's a fine dayYou promised we'll be going together to the hanamatsuri