Living out on the high seas for months on end it a stressful situation, especially for chaps who just crave the touch of a honey. This simple need transforms with time, and becomes much more then that, with freighting imagination taking place, and replacing it with hellish dreams. Thats exactly what happened to Yuki, who was brought aboard the ship originally as an assistant to the Commander. He however wanted much more then that, so this dude ordered her to please him in every way. For her to disobey would have meant great dishonor so she complied with enthusiasm. Its awesome what they get away with.