Bring up Asuka Langley and Ayanami Rei the way you desire. Let her develop the strengths that would make her into a dream girl.
Hold your Nintendo DS vertically, and use your touch pen to design a schedule for her. There are 10 aspects in which she can grow and by the end of the game, depending on her development, you would get a different ending.
Decide on what to put into her schedule on her school days, how to celebrate holidays such as Valentine days and Christmas with her. Dress her appropriately for the activities, the more she develops, the more cosumes you could get for her.
With all the different endings, this game deserves to be played repeatedly for numerous of hours.