Utau's first Guardian Character that is seen is the conflict-loving, devilish girl, Il. She dislikes peace and becomes very bored if the current situation is peaceful. She tells El at one point that a Guardian Character that doesn't even Character Transforms is not needed. Soon after, El left Utau, and ll actually became so bored that she wanted El to return so she can tease her. She also tends to be very rude to others, in particular to Yukari Sanjo. This was shown when she called her a old woman when she's actually in her 20s. Her and El's names are usually pronounced "Iru" and "Eru". The name "Il" is also the last two letters of the word devIL.

During Character Change with Il, a pair of bat wings sprout from Utau's back, making the melody that she sings pull out X Eggs. However, the amount of X-Eggs she can pull out is not large and the owners of these eggs have to hear her sing live.

She can also use this Character Change to fly and send out a powerful wave of butterflies to attack.

When Utau transforms with Il, she becomes the devil character Lunatic Charm. This represents the rougher, more cunning aspect of her. This transformation first appears in Episode 22 of the anime.