Tenchi Muyo! Ryo-Ohki

Tenchi Masaki, now seventeen, grew up hearing legends of how his ancestor had sealed a demon inside a cave seven hundred years earlier with the aid of a sword. Tenchi visits the cave out of sheer curiosities and discovers the legendary sword inside. Inadvertently releasing the demon, who is revealed to be a space pirate by the name of Ryouko Hakubi, he removes the sword since he believes the tale to be nothing more than a fairy tale. She assaults Tenchi, angry at having spent so much time imprisoned, but he repels her with the sword, awakening his inner power. As a result of what she observes, Ryouko decides to spend the night with her unlikely savior. As though in a chain reaction, additional alien ladies gradually get into contact with Tenchi and start living with him, including Washuu Hakubi, a wisecracking genius, Sasami, Aeka Jurai Masaki, a sweet young sister of Aeka, and Mihoshi Kuramitsu, a ditzy Galactic Police Officer. Tenchi learns more about his heritage, his unexpected strength, and the impending danger hiding beyond the skies through his interactions with these five women.