Tenchi Muyo

Tenchi Masaki is a high school student and is training to succeed his grandfather as caretaker of the Masaki shrine. His grandfather, Katzuhito, has told him of the legend of why the shrine was built. 700 years ago a demon came from the sky and ravaged the countryside till a hero named Yosho arrived and finally defeated it. Then he sealed the demon Ryoko away in a cave with a magic sword being part of the seal. The Masaki shrine was built to watch over the seal. One day, Tenchi's curiosity gets the best of him and he goes to investigate the cave and the legend. He finds the sword and deep in the cave, he also finds the mummified remains of what must have been the demon, which comes to life and chases after Tenchi. Tenchi manages an escape and closes the cave on his way out. Sometime later, at school Tenchi falls asleep during recess and wakes up to find it is night and nobody is around, except a beautiful woman who introduces herself as the demon Ryoko. A mummy no longer, she tells Tenchi that it was cold and lonely in the cave and that she needs to take out her frustration, on him. She goes after Tenchi with different kinds of energy attacks and he manages to dodge them as she chases him all through the school. When he is finally cornered, the sword that he took from the cave activates and repels Ryoko's energy sword. It also takes control Tenchi and slices Ryoko's hand off, taking from her the jewels that are the source of her power. When Tenchi apologizes, Ryoko smiles, regenerates her hand, and retreats. When Tenchi gets home, he finds Ryoko in his room, waiting for him.