The player is in the medical major. Under the threat of your father, you go to an all-girls high school and spent a month there as a doctor at the health department. Of course, a male doctor in an all-girls school is pretty odd and rare. Basically, during your month of stay, you will meet a total of 5 girls, each having their own personality and problems/troubles in love. So, as a school doctor, you have to somehow see to their hearts, help them somehow and make them feel happy. Maybe you will end up having a relationship with them too...
You and everybody else go to school on weekdays as well as saturday morning. You will have a chance to walk around school before school starts, lunch break, and after school. Each break has a different time limit, and during that time limit you can walk around school and by chance you may be able to meet girls, chat with them, have lunch with them, etc. As you do things or say good things to them, their impression will increase, and certain events will appear only if the impression gets to a certain point. On Sundays, you can choose to go out with a girl for a date, or you can choose to loiter in school.
[from Anime Densetsu]