The Pie Monster is attacking the city and only Sailor Moon can stop it, or so we think. After challenging the Pie Monster to a fight in Japanese(yes, she speaks Japanese in this) she is promptly pied in the face.
That's just the beginning of the bombardment. Sailor Moon is pelted hard with almost 2 dozen creme pies.
In between the pie action she is engulfed by pink slime, and has her chest pied! Her uniform and lovely pig tails are ruined!
After a couple more pies Sailor Moon is soundly defeated with a bucket of super chunky purple slime. It doesn't get any thicker than this.