An unusual snow storm/blizzard hits the town and the Sailor Senshi discover that the evil Princess Snow Kaguya wants to freeze the entire Earth. The Inner Senshi, with the help of the three Outer Senshi-excluding Sailor Saturn-must defeat her. Meanwhile, Luna falls in love with a human astronomer named Kakeru Ozora whose girlfriend, Himeko Nayotake, is an astronaut about to go into space. Kakeru becomes ill and Luna wishes she could be a human to help him.