Kaguya's species

"It seemed as if she were made of light, for the house was filled with a soft shining, so that even in the dark of night it was like daytime. Her presence seemed to have a benign influence on those there. Whenever the old man felt sad, he had only to look upon his foster-daughter and his sorrow vanished, and he became as happy as when he was a youth."

- The Japanese Fairy Book (1908)

Kaguya's species is a sapient species of luminous beings which inhabit Luna.

A member of this species, Princess Kaguya (a.k.a. Princess Moonlight) was sent to Earth and lived among Humans for twenty years.

Biology
The inhabitants of Luna are (or can assume the form of) beautiful humanoids who emanate light from their bodies and are able to either disappear or become invisible at will. It is also possible that their presence might have a soothing or even a rejuvenating effect on those around them. They are born very small, but their growth rate is unusually fast compared to a Human child. After drinking from the elixir of life, they become immortal.

Members of this species also appear to have supernatural abilities that render Humans powerless against them. Attempts to shoot arrows at them have resulted in failure, as if the moon beings could control the archers and/or the arrows themselves.

History
At some point in Medieval Japan, an elderly bamboo cutter noticed a mysterious light emanating from one of the bamboo stems. Inside it, he discovered a tiny child, only about three inches tall. Since the bamboo cutter and his wife had always wanted a child, they regarded this as a blessing and raised the girl as their own. She grew up to normal size in three months and was considered exquisitely beautiful. Meanwhile, the bamboo cutter started to find gold coins inside the bamboo notches, and thus became a wealthy man.

Although her beauty earned her a number of potential suitors, including five knights and even the Emperor of Japan himself, Kaguya insisted that she couldn't marry anyone on Earth. For many nights, she would stare quietly at the moon and weep, and one day confessed to her foster father the truth: that she was not from Earth, but a native of the moon, and that her people would soon come to take her back to the Capital of the Moon.

When the time came, a cloud descended to Earth from the moon, containing a flying chariot from which luminous beings emerged. Among them was the king, Kaguya's biological father, who explained that the moon beings had sent her to the Earth twenty years before, and rewarded the people who had taken care of her by placing the gold in the bamboo notches for the bamboo cutter to find.

Appearances

 * "The Tale of the Bamboo Cutter", a.k.a. "The Bamboo-Cutter and the Moon-Child" (Japanese: 竹取物語), by unknown author (9th century)
 * Princess from the Moon (1987)
 * The Tale of the Princess Kaguya (2013)