AH-HA-HA-HA-HA-HA-HA-HA-HA-HA-HA!!!
I can see it now...
"Welcome, newcomers!" declared the Demon King. "First, as a test of your stamina, there will be a pillow fight with this Elder (The Princess). If you are able to wear her out and put her to sleep, you shall be rewarded with this chest of treasure, these powerful magic weapons and a complete set of knitted pajamas made by this Elder herself!"
Later on...
"I can't believe it!" exclaimed the Demon King. "ALL of the newcomers were defeated by the Princess!?"