While enjoying the flower gardens, Sailor Moon (Usagi) and friends encounter an old childhood friend of Mamoru's: an alien! He's come back to give Mamoru a special flower, but doesn't like Usagi and the rest of the planet's inhabitants. Sailor Moon must defend the earth from the evil Kisenian Flower he's brought back... before the evil vines and blossoms overrun the planet!
The wicked Badiyanu has come to capture all Earth's children to gain enough power to absorb the planet in her Black Dream Hole. The Black Dream Hole is in Badiyanu's castle and absorbs the dream energy from children. The more children Badiyanu kidnaps, the larger the dream hole gets. The Sailor Team must save Earth's children and prevent the Black Dream Hole from enveloping the entire planet!