Kimomen Demo Kyokon nara School Caste no Chouten ni Tateru!? Gakuen Ichi no Motekawa Shuudan ni Tanetsuke Shimakuri! Yume no Gakuen Harem! (2012)

In the near future, where men's penises and purposes had shrunk to miniscule size, the birth-rate had dropped to dangerous lows. Everything came down to one valuable asset: having a massive cock! Big, fat, thick, fully engorged wangs are worshipped by a female society deeply in need of satisfaction! Enter our hero, an unattractive guy with the lowest status of anyone at school... until it's discovered that he's got a cock like Popeye's forearm! From loser to lover, celibate to celebrated, experience the dream harem-fucking rise of one lucky man born in the right time, at the right girth!