Basicly it boils down to trial and error, very linear.
The game lets you choose at its strt whether you want to play as male or female (keep in mind I only played the guys side). The object is to meet people and get them to like you, bottom line. During missions you have conversations with people, you select how to respond using either the DS controls or the stylus.
You'll often juggle several scenarios at once to try and keep everybody happy. But there's the huge downfall of this game, there is no player control, the game is extremely linear and doesn't give you any freedom as the player. In most missions you can only get through them one way, always with the same outcome. And then, if you select the wrong response you'll end up with a "GAME OVER" screen.
And what makes them very annoying is that many times what you think would be the best awnser is actually the worst, and you can offend NPC's very easily. Often you'll get stuck with a selection of responses, and all of them are bad or all of them seem like something good to say. You'll come to count on that the longer a mission is the more times you'll repeat it.
It's very unfortunate, the graphics and character animations are done very well but there is no substance to the gameplay.