Serena and Rini are befriended by a mysterious foreign woman who accompanies them to the Azabu-Juuban summer festival. Unbeknownst to them, their acquaintance is a visiting princess who is being pursed by both her government and Hawk's Eye.
Fisheye discovers Rini communicating with Pegasus, but refuses to cooperate with Zirconia's plans. As Hawk's Eye pursues Serena for her Dream Mirror, Zirconia decides that the Amazon Trio have outlived their usefulness.
On the eve of his school's athletic meet, Kelly worries about the box horse, the one obstacle he is unable to clear. JunJun approaches him with the intention of taking his Dream Mirror, and offers to be his coach.
PallaPalla's magic causes Serena and Rini to switch ages, turning Serena into a child and Rini into a teenager. While Rini is thrilled with her new body, she is distressed to discover that she can no longer call Pegasus.