Sailor Moon R: The Movie - The Promise of the Rose

Tokyo is struck by a sudden attack from the flower monster Wisteria, which begins draining people's life energy. The Inner Senshi leap into battle and successfully stop the monster, but their victory proves short-lived. Suddenly a new enemy appears: an alien named Fiore, accompanied by a giant Kisenian Blossom. They attack Sailor Moon, but at the last moment Tuxedo Mask takes the blow himself, saving her. Fiore, who turns out to be an old friend of Mamoru's, carries his body off to an asteroid approaching Earth in order to heal him there.

It emerges that Mamoru once gave Fiore a rose, and in return Fiore promised to find a unique flower for him. In his search he traveled across the galaxy and came upon the Kisenian Blossom, which took control of his mind. Now Fiore has returned to Earth intent on destroying humanity, whom he blames for Mamoru's loneliness. His plan is to cover the planet with flowers that will drain people's energy, dooming them all.