Kaguya

About
Kaguya is a female member of an unknown race from far away. She wasn't born in The Continent and belongs to an incredibly advanced civilization that is light years away from it. Her race seems to be largely similar to humans, both in appearance and in anatomy, as they even rely in copulation the same way as humans do for reproduction.

She made appearance in Sengoku Rance, where her spaceship happened to crash in Mikawa in JAPAN, breaking down in the process. Using her advanced technology, she fooled the townsfolk but claiming she was a Goddess and using her technology to heal wounds and cure diseases in exchange of food and other offerings, getting some fame as a mythical being and earning the name of "Kaguyahime"(Princess Kaguya). Rance, curious about this entity, payed her a visit and he managed to uncover her identity, forcing her to reveal that she was no Goddess but from a race of outer space. She claimed that she would be able to repair her spaceship if she could fix it by using the Repairing Device of the ship, which broke down as well. Luckily, basic raw materials like coil, iron and a few others are enough to repair it, so Rance offered to bring her all the materials she needs in exchange of having sex with her, much to Kaguya's astonishment.

sometimes pays her a few visits to bring her food and to be healed by her. Eventually, Rance finds all the materials she needs and Kaguya is able to repair her spaceship. He then has sex with her in the ship with the unexperienced Kaguya, who was having her first time with Rance. After it's over, Kaguya leaves and contacts with her boss. It is revealed through the conversation with her boss that Kaguya belonged to a scouting unit meant to confirm if The Continent had intelligent life so that her race could perform a planetary invasion to enslave them. Aware that with their primitive technology they would get destroyed with ease, she lied to her boss by stating that there was not signs of life in the whole piece of land and an invasion would be a waste of time and resources.

Trivia

 * Strangely enough, Kaguya refered to The Continent as "Ludo-Rathowm's Land", suggesting that her race knows about Ludo-Rathowm somehow.
 * The technology from her spaceship was so advanced even someone like Maria, who's considered a genius in the continent, was incapable of comprehending its complex machinations.