Beth (ベス Besu) is the first and last Platinum Princess candidate for the Eternal Tiara. She is the Princess of the Fairy Kingdom.
Beth is a headstrong tomboy and a loner, prefering to do things her own way on her own. She refuses at first to become friends with the other girls, only accepting it after many attempts from Cocoloo. You find out as the series progresses that she is very kind and sweet and cares for her people in a way that you don't see in the others. She is quick to accept any blame for any and all problems that she or her people cause. She is in fact a very strong and responsible ruler. She is the shows Tsundere denying any positive or feminin traits that are pointed out.
Beth comes in during episode 14 after a leap of absence. At first she seems friendly with the other girls, until she kidnaps Cocoloo and tries to force her to give up her spot as a Platinum Princess candidate. After Cocoloo refuses and the other girls rescue her, she becomes cold and distant toward them, saying that she must become the Platinum princess no matter the cost.
The other princesses find out that a demon called Diablos is attacking her home and her father, the giant tree sustaning all life in the Fairy Kingdom, and slowly killing him. Beth once tried to rally all of the inabitants in Fairy world to fight against him, but they were too frightened and refused. She did not blame them decided to defeat him on her own and never to rely on anyone ever again.
It takes a long time for her to accept the help that the other princesses offer, but once she does they attack Diablos as a team and find that they needed the power of all of their pure hearts to defeat him. After he is dead she sees her father and allows him to rest. We see her cry and smile, a side of her that is new to the viewer.
When the group discusses the Platinum Princess candidacy around the end of the series, Beth says she has no interest in the Eternal Tiara, already having her wish to save Fairy Kingdom granted, despite later finding out that she, like all of the other princesses, is also seventeen.