There are a ton of collectibles to find in The Legend of Zelda: Skyward Sword HD, but some of the trickiest ones to get your hands on are Gratitude Crystals. You'll typically receive these crystalized bits of happiness when you help out the many residents of Skyloft, and they can be traded in for some rare rewards, making them among the game's most valuable collectibles.

　　Nearly every denizen of Skyloft has some sort of problem or side quest they need help with, including one unusual request involving the Knight Academy's bathroom. Here's what you need to do to complete this side quest and earn some more Gratitude Crystals. For more Skyward Sword HD guides, check out our full guide roundup, which also includes beginner's tips and heart piece locations. Be sure to also read our full Zelda: Skyward Sword HD review.

Haunted Bathroom

　　Regardless, investigate to discover a spirit is in dire need of some paper for a most…unsavory deed. From there, return to the daytime and look for Cawlin. He has a love letter that he wants to pass on to Karane. You can opt to deliver the letter as promised; this will ultimately lead to a cutscene where Karane talks to Cawlin and Pipit intervenes, revealing his true feelings for her. Karane will say she feels the same, and Cawlin will run off heartbroken. His sadness is your fortune, however, as you'll receive five Gratitude Crystals from Karane.

　　Alternatively, you can choose to give Cawlin's letter to the spirit in the bathroom. Return the following night and visit Cawlin in Groose's room, and you'll see the spirit from the bathroom caressing his head. The spirit will say she was so moved by the letter that she's fallen in love, and you'll receive five Gratitude Crystals as thanks. Regardless of who you decide to give Cawlin's letter to, you'll ultimately get the same reward (though Cawlin will end up miserable no matter which choice you make).

　　For details on the rest, be sure to read our Gratitude Crystal quest roundup, including walkthroughs for each one, locations for individual Gratitude Crystals, and the rewards you can get from exchanging them.