Storeroom Key
The Storeroom Key is a special item found in Paper Mario.
After Mario obtains the third Star Spirit, Skolar, he goes back to Toad Town, as usual. To his surprise, there's local havoc going on, as Shy Guys have random started to appear and do mischief all over the place, stealing from townsfolk and just doing pranks overall. As Mario is walking over to Harry T.'s shop, a Shy Guy comes running out of it. Mario soon finds out this Shy Guy has stolen Harry T.'s Shop Storeroom Key, and is unable to open the storeroom. The Shy Guy, additionally, has hidden the key somewhere in the Shy Guy's Toy Box.
As Mario approaches the room which the stolen Storeroom Key lies, Kammy Koopa flies by on her broom and uses her magic to place an enemy or an item to "guard" the place. What Kammy Koopa makes appear is influenced by Princess Peach's answers to what Mario dislikes during Chapter 3's end. Kammy Koopa isn't exactly sure about whether Mario truly hate what she places, but has no option but to follow the commands of the Koopa King. Mario, brave as he is, recovers the Storeroom Key and gives it back to Harry T., who gratefully lets Mario whatever is inside the Storeroom for him to keep. While this sounds pretty minor to the story, it's actually needed for the storyline to progress: Inside Harry T.'s Storeroom was the Toy Train, which would later allow Mario to travel from one station to another inside the Toy Box.
