Kakeru Ozora was an astronomer who dreamed of a princess who lived on the moon. He discovered a new comet which he dubbed Princess Snow Kaguya and watched with obsessive fascination, and when he found a piece of it that fell to earth he took it home to study. Unfortunately for him, the comet was the vehicle of an ice creature determined to freeze the entire Earth, and the fragment he found slowly drained his energy.

After he saved a sick Luna from almost being hit by a car, he took her home and tended to her until she got better. She fell in love with him and wished to become human; through the power of the Silver Crystal her wish was granted and she took Kakeru to see the moon from space.

His name literally means "flying in space."

(Source: WikiMoon)