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http://ds.gamespy.com/nintendo-ds/valentines-day/
I have to link to GameSpy because I just can't find this on Amazon or whatever. In fact the first page of results is a bunch of ROM sites, and I'm not linking to those. If the most notable mentions of your game--SEVERAL of them--are all ROM sites, then that's proof your game was...not well received, shall we say.
In this game, you give gifts to girls. No, really. You have an incoming line of gifts, only the last four of which you can gift. These include stuffed animals, jewelry, shirts, cookies, cars, books, and flowers. You have some number of girls, nine of which will be active at any one time. Each has their own set of likes, dislikes, and personal color. Give them gifts they like or gifts they don't dislike but that match their color, don't give them gifts dislike, don't make them wait too long for a gift and leave angrily (or you'll get a game over).
Comments
...It doesn't sound like a sim game though