"I'm sick of waiting. Waiting to grow up, waiting to be a Senshi, waiting to be a lady."
The only daughter of King Endymion and Queen Serenity, Chibi-Usa has lived a life that is paradoxically both charmed and filled with difficulties. Although she is 917, she spent the first 900 years of her life stuck in the body of an elementary schooler, a condition that subjected her to hearing suspicious rumors from her people and the press. Moreover, her parents' position as the heads of a united world government meant that where other children were often showered with love and attention, Chibi-Usa had to make do with what time they had for her in between their numerous responsibilities. Still, as the princess of Earth, Chibi-Usa was never in want of anything and was always attended to by the four Sailor Guardians.
Things became worse after the arrival of the Black Moon family as her mother was forced into a state of suspended animation and her friends and family were laid low by Nemesis' attack. Running to the past to get help from Sailor Moon, Chibi-Usa soon found herself bonding as much with her mother's less-distant past self as with the imperial Neo Queen Serenity. After the defeat of Black Moon, Chibi-Usa remained in the past and trained with Sailor Moon for two more years. It was while living in the past that Chibi-Usa finally began to become a young lady and met her true love, Helios.
When Lady Serenity entered her teenaged years at last and was reunited with the love of her youth, she begged her father to allow her to attend a "normal" school instead of going to private tutoring sessions with the Inner Senshi. Reluctantly, her father relented and allowed her to attend a public school with Helios and her four guardians, the Sailor Quartet. There, Chibi-Usa meets Seisui, a lonely and broken girl who, like Hotaru before her, just seems to need a friend to reach out to her. Seisui seems to accept Chibi-Usa's warmth gratefully, if a little reluctantly, and Chibi-Usa sees herself as carrying on her mother's tradition of being a friend to those who have none. What Chibi-Usa doesn't realize is that Seisui's friendship may not be as genuine as it seems, and concealed beneath her seeming gratefulness is a dark purpose...