Breed! Breed-Island.

The player takes the role of Jun, a young man that falls overboard from his ship during a storm, only to awake on an island that is inhabited by young women. While he initially thinks he is in heaven, it is revealed that he is the creature known as a "man" that is destined to arrive at the island once every generation to help all women of age to "create new life". While he takes the responsibility with gusto, questions begin to form in our protagonist's mind. Why is the island only inhabited by young women? Why are there no adults or elderly around? More importantly, how could such an island remain uncharted?