Growing up, Tenchi Masaki always heard stories about how his ancestor used a sword to seal a demon inside a cave 700 years ago. When his curiosity gets the best of him, Tenchi heads to the cave, and much to his surprise, he stumbles upon the very sword from the legend. Convinced it's all just a fairy tale, he lifts the blade, unwittingly releasing the demon - a space pirate named Ryouko Hakubi. Enraged at being trapped for so long, Ryouko attacks Tenchi, but with the sword, he's able to fend her off, awakening his own inner power. Intrigued by her unlikely rescuer, Ryouko decides to crash at his place. Before long, more extraterrestrial women start appearing in Tenchi's life, almost as if drawn there by some unknown force. They include the idealistic Princess Aeka Jurai Masaki from the planet Jurai, her sweet younger sister Sasami, ditzy Galactic Police Officer Mihoshi Kuramitsu, and wisecracking genius Washuu Hakubi. Through his encounters with these five women, Tenchi begins to unravel mysteries about his ancestry, newfound powers, and a looming danger that threatens the universe.