Chibiusa's first appearance in this volume is when Diana travels back into the past to investigate the disturbance because she is worried about Chibiusa. She ends up having her crescent moon destroyed. She becomes a regular cat without the faculties of speech. By the time Chibiusa realizes something isn't right, Diana is already gone and Chibiusa is even more alone.
Later she knows that things are even more wrong as Diana is killed in the past. She approaches the Neo Queen and they explain that Diana begged to be able to go to the past to investigate. Chibiusa doubles over in pain as Usagi is hit by a blast in the present day and the Queen takes her to show her the bodies of the sailor senshi who are all comatose, and slowly fading away. Her father is among them.
She tells her mother flatly that she's going to the past, but the Neo Queen protests that it's too dangerous (the big sissy). Chibiusa tells the Queen that the pain in her chest is the pain of all those across time begging for her help. It is her duty and her mission. She will not be persuaded.
At this point Sailor Ceres, Sailor Vesta, Sailor Pallas, and Sailor Juno arrive in the future and introduce themselves as the Sailor Quartet, Chibiusa's protectors and court.
The Queen gives her permission to Chibimoon and tells her that she'll find her answers beyond space and time: beyond the galaxy. Chibimoon and her senshi depart.