Diamond true name unknown is Amu039s fourth Guardian Character with a musical flair. She became an X Egg when Amu disliked all the changes that were happeningand then hatched as an X Character after Utau finds her egg and character tranforms with her as Dark Jewel. Since Amu did not know Dia039s real name Amu just calls the Guardian Character quotDiaquot a shorter form of quotDiamondquot. When Amu convinces Dia that she can change the 039Xmark039 is lifted and a Character Transformation sparks as the two become quotAmulet Diamondquot. Dia didn039t like Amu because she didn039t have a sparkling heart like Utau but finds out later that Amu does so she goes back to Amu. Afterward Dia goes back into her egg to slumber until Amu quotshines againquot. She rarely but does come out in some episodes once in a while.