Luna may be a very special cat but even she has lessons to learn about love. She meets a young but ailing astronomer, Kakeru, who has discovered a comet streaking towards Earth. He names the comet after the mythological Princess Snow Kaguya unaware that it heralds the return of the real Princess Snow Kaguya after 450 thousand years. Join Luna, Sailor Moon and the Sailor Scouts as they battle to keep Princess Snow Kaguya from ruling the Solar System.