During a solar eclipse, a mysterious floating circus tent appears in the sky over Tokyo. Meanwhile, Chibiusa is fascinated by a Pegasus who appears to her in a dream.
When Reika returns from Africa, Usagi becomes concerned that she and Motoki are having relationship problems. Meanwhile, Tiger's Eye selects Reika as a target.
Usagi and the girls are shocked to find out that Minako is dating two boys at the same time, but little does anymore realize that her suitors are Tiger's Eye and Hawk's Eye.
Usagi and Chibiusa 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.
While Fisheye targets Mamoru, Queen Nehellenia appears before the Amazon Trio and warns them that without the Golden Crystal, they will soon revert to their animal forms.
Fisheye discovers Chibiusa communicating with Pegasus, but refuses to cooperate with Zirconia's plans. As Hawk's Eye pursues Usagi for her Dream Mirror, Zirconia decides that the Amazon Trio have outlived their usefulness.
Ami becomes obsessed with a tune she found on the internet, and writes lyrics to it. Meanwhile, VesVes of the Amazoness Quartet targets the tune's composer.
Makoto and Minako both fall for an attractive kindergarten teacher, but Minako's all-out attempts to ingratiate herself with him soon annoyed to Makoto.
On the eve of his school's athletic meet, Kyuusuke 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 Usagi and Chibiusa to switch ages, turning Usagi into a child and Chibiusa into a teenager. While Chibiusa is thrilled with her new body, she is distressed to discover that she can no longer call Pegasus.
As Chibiusa becomes even more enamoured of Helios, Usagi and her friends realise that she is in love, and are determined to discover the identity of her crush.