The Secret of the Two Sorceresses

Bestseller from Japan!
The third book about the magical adventures of the kitten princess.
All the children in the kingdom of Artesia are preparing for a grand event – a masquerade ball! Lala and her friend Polly have thought through their looks and prepared their outfits.
However, they did not expect that uninvited guests would arrive at the celebration! Two sorceresses desperately want to get their hands on the princess's magical medallion for some reason. And they are ready to resort to trickery for it!
Who are they? And why do they need this magical item so badly?