Pretty much this game is a Marmalade Boy Date Sim, the object is to get one of the three guys, Yuu (blond hair), Ginta (Black hair), Kei (purple hair).  you say and do things to get them to like you, and after your three month period, ending on valentines.  If you've seen the Anime, you'll recognize some scenes and settings, and can kind of guess what kind of reaction to aim for.
For me, I memorized the kanji for the main characters:
光希 = Miki (your character, lovable girl who plays tennis, and is caught up in several love triangles)
遊 = Yuu (Blond Love interest, very mysterious lives with miki due to their families exchanging partners)
銀太 = Ginta (Brown haired love interest, liked miki in junior high, but had her turn against him due to a misunderstanding of his feelings)
茗子 = Meiko (Miki's best friend, Girl with long brown hair, has issues with her crush on teacher)
亜梨実 = Arimi (Blue haired Rival for Miki wants to get Yuu, and uses Ginta to make Miki jealous)
蛍 = Kei (Purple haired Third Love interest, works in ice cream shop plays piano likes miki and is jealous of yuu)
三輪 悟史 = Satoshi Miwa (Black haired Upper class man who has a deep friendship with Yuu and a heavy crush on Meiko)
六反田 務 = Tsutomu Rokutanda (short purple hair, Ginta's cousin who has an obvious crush on arimi)
名村 慎 = Shin'ichi Namura (Miki's Teacher, loves Meiko but can't show it because of the student teacher issues, also miki's tennis coach)
It is a pretty fun game, but alas still no translation for it yet, but I hope this info may help you enjoy it a little better

Aww, sounds like a fun game to play. It's too bad I don't know Japanese either. x3

There are a lot of games out there in the RGR that I'd love to play if I could understand Japanese. You can see my profile for some of them. I might have to add this one too. x3

One of the reasons I wanted to go into video game design was so that I could be able to translate great games like this and convert it for others to enjoy.  (also the main reason I got into learning some Japanese in the first place)

I'm pretty good understanding things I hear, but I'm still a long way learning two different languages, in addition to the programming languages I've been learning as well)  different languages, in addition to the programming languages ive been learning as well)