Nangoku Sakunyuu Island: Ninshin Sasete!? Chichi Shibori

The main character drifts ashore to the island, where only girls with big breasts live. He is welcomed by them, and starts to live with them. One day, a man, whose job is to milk the girls, has gone missing. The girls need him because they make a living by selling their breast milk. As a result, the main character is forced to take over the job. He has a good cause to ejaculate inside the girls... on business? Anyway, his sex life soaked in milk starts....
(Source: ErogeShop)