Ringetsu 1

Naoto Rindo is not your average guy. Not only is he the scion of one of the wealthiest families in Japan, he's afflicted by a curse: every third generation, the family's men are unable to produce a male heir--except with a woman from the Hizuki family. Naoto's grandfather tells him he only has one month to get one of the Hizuki sisters pregnant, or he'll be expelled from the Rindo clan! Sarcastic Shino doesn't want anything to do with him, studious Mizuna is always lost in a book, and sweet Ayumi is too shy. Will Naoto manage to seduce one of the busty Hizukis and save his family's future?