User summary (with release information from Japanese Wikipedia):
A boy-dating high-school romance simulation game from Konami. The player takes the role of a girl entering high school, where she meets several attractive boys. The goal of the game is to have one of the boys confess his love for the player as the three years of high school comes to an end.
Each week, the player can choose what to concentrate on: studies, exercise, socializing and so on, activities that will raise and lower various stats. Depending on the player's stats, random encounters with certain boys will occur, and once the player knows the name of a boy, she can invite him to dates.
The game was ported to Nintendo DS in 2007, and got a full-voiced version in 2009.
Source: Wikipedia, "ときめきメモリアル_Girl%27s_Side," available under the CC-BY-SA License.