Princess Sara is a minor character from Pokémon: Advanced Challenge.
Pokémon the Series: Ruby and Sapphire
Princess Sara, along with her parents, the King and Queen of the Mirage Kingdom, found themselves involved in an attempted coup d'etat by the magistrate of the Mirage Kingdom, Colonel Hansen, who wanted to take over both the Mirage Kingdom and the Togepi Paradise that the kingdom was sworn to protect for his own evil purposes. She was relaxing by the garden fountain when she heard something, and noticed an airship arriving at the kingdom's airport, not realizing that on board were Pokémon Trainer Ash Ketchum and his friends, along with Hansen's fellow conspirators, Team Rocket, who were luring Ash and his friends to the kingdom as part of Hansen's plot since they knew Misty had a Togepi that Hansen could use. Later, as she is tending to the flowers with her guardian, Miranda, she found a Togepi, badly injured, having just landed in the fountain, having heard the splash when it landed. After showing it to Miranda, Sara believed it was the Togepi she needed to become Queen after her parents stepped down from the throne due to the kingdom's tradition in regards to Togepi. As she was showing the Togepi to her parents later on after tending to its injuries, it was then she and her parents met Ash and his friends from his journeys through Kanto, Johto, and Hoenn: Misty, Brock, May, and Max. After it was revealed that the Togepi that Sara found was actually Misty's, Sara explained about why Togepi were so sacred in the Mirage Kingdom, before asking Misty and the others to leave before Misty's Togepi could be used for evil purposes. However, before they could leave, Colonel Hansen appeared with Team Rocket to capture Misty's Togepi.
During when Misty's Togepi protected everyone from an attack from Hansen's Shedinja and Ninjask, Sara was transported to the Togepi Paradise with Miranda and all of Ash's friends, and was horrified to see how Hansen's evil intentions were causing the paradise to become a dying landscape as a result and leaving all the Togepi in depressed states. Soon, Misty's Togepi was taken back into the Mirage Kingdom by Hansen when he attacked the portal to the Togepi Paradise, leaving Sara and the others trapped, until the Togepi there were able to transport them back to the Mirage Kingdom as well, only to learn by then that Hansen's coup had succeeded as Sara's parents had been locked up in the dungeon, and Hansen was using Misty's Togepi to name himself the new King. Deciding to split up to try and stop Hansen and save Sara's parents, Sara went with Ash, Misty, and May, while Brock and Max went with Miranda. They encountered Hansen as he tries to open up the portal to the Togepi Paradise, and engaged him in battle. Ash's Pikachu was easily able to take down Hansen's two Ninjask, but due to his Shedinja's Wonder Guard ability preventing any damage save for its weaknesses, things seemed hopeless, until Misty's Togepi protects everyone, then with the aid of the Togepi from the Togepi Paradise, evolved into Togetic, before Misty was able to take down Shedinja with her Gyarados and its Flamethrower, due to Shedinja being weak to Fire-type moves. Sara's parents, having been found and released by Miranda, Brock, and Max, arrived to have Hansen arrested for his treason and led away to possibly be imprisoned for life, or executed.
That evening, as Misty bid her Togetic a tearful goodbye as she released it to remain in the Mirage Kingdom to defend it and the Togepi Paradise from future threats, one of the Togepi remained behind. It turned out, that Togepi was the one destined for Sara so she could become Queen. With her future as the next Queen of the Mirage Kingdom now ensured, Sara was grateful to Ash and his friends for all they had done to help her and her kingdom out and wished them good luck on their journeys.