Before menstruation, the breasts swell and become sensitive, and the information that it is easy to get horny is verified by school girls in a natural style. A nipple that is so sensitive that it hurts just by rubbing it reacts hypersensitively just by poking it. Furthermore, when she rubs her tightly stretched breasts, she begins to get excited beyond reason due to the pleasure that lies ahead of the pain. And while refusing, the body before menstruation begins to ache and gradually estrus.