Utau has two charas,Iru and Eru. None of them is a X-egg :) they're normal charas
But Amu's fourth egg,Dia,get's a X on her,so she becomes a X-egg. Dia runs away from Amu,because she desn't accept Amu as her owner. Then Utau finds Dia,and then Dia kinda becomes Utau's egg,but it's really Amu's egg.
I don't know if this was understnadable,but the point is that Utau's eggs are not X-eggs xD
