Plot: The episode starts with Usagi dreaming about her and Mamoru getting married. She abruptly wakes up to find her bed wet. Luna accuses her of peeing in bed, but they soon discover that Chibi-Usa was the culprit when she snuck into Usagi's bed while Usagi was sleeping.
The scene then cuts to the Black Moon Clan's spaceship. Wiseman appears, and tells Rubeus that the Rabbit (Chibi-Usa) will appear that morning by the walking bridge in town. Rubeus says he will send the Phantom Sisters after her. He then asks Wiseman about the status of taking over Crystal Tokyo. Wiseman says it is not going well. Their army cannot reach the Crystal Palace because four enemy warriors are sending great amounts of energy outside to defend the castle walls. Rubeus tells Wiseman about the Sailor Senshi he is encountering in the Tokyo of the past, and wonders if they are somehow related to the four warriors of the future.
The next morning, Usagi is beating her sheets clean on a clothesline while Shingo taunts her for wetting the bed. Usagi exclaims that it wasn't her, it was Chibi-Usa. Shingo scoffs at her for blaming a child. Suddenly, Chibi-Usa is seen walking from the house to the street. Usagi confronts her, but she runs off. Luna then comes up to Usagi and says that Chibi-Usa must have been lonely; that was why she crawled into Usagi's bed last night. Luna says they should go after Chibi-Usa and bring her back.
Next we find Chibi-Usa sitting on the steps leading up to the pedestrian bridge. She pouts about wetting the bed the night before, and remembers a time from when she was smaller when she wet the bed and her mother comforted her. This causes her to miss home again. She then remembers Puu's (Sailor Pluto's) words about her not being able to time-travel back home just yet. Chibi-Usa defies this and tries to go back home anyways. She starts floating upward towards the gates of time, but then the cloud suddenly disappears and Chibi-Usa falls back to the ground. Frustrated that she can't go home, Chibi-Usa starts crying and her energy burst appears.
Luna sees Chibi-Usa's energy and panics. Meanwhile, Berthier appears at the bottom of the stairway to capture Chibi-Usa. As she starts to move toward her prey, Koan suddenly appears at the top of the steps and claims she is the one who will capture Chibi-Usa. Both of them move towards Chibi-Usa, and the poor girl doesn't know what to do. Suddenly, Luna-P rolls into Berthier's path, and she trips and falls down the steps. Chibi-Usa sees her chance and hightails it down the stairs with Luna-P following her. Koan is too fast for her; she appears in front of Chibi-Usa waiting to catch her. Luna-P throws itself at Koan in an effort to protect Chibi-Usa; however, Koan pushes the toy away. Chibi-Usa thinks she is doomed, but at the last second, Luna appears and scratches up Koan's face. Chibi-Usa escapes. Both sisters are furious at the Rabbit for damaging their makeup.
The scene cuts to Rei, Ami, Makoto and Minako window shopping. They exclaim that Usagi is late to meet up with them and go shopping, and they wonder if something bad happened or if she overslept. Just then, Luna limps up to them, badly beaten up from her encounter with Koan. She tells the girls and Artemis that Chibi-Usa is in trouble and was last seen near the pedestrian bridge. The four girls run off to find her while Artemis stays behind with the wounded Luna.
Meanwhile, Usagi notices Chibi-Usa sneak into a construction site. She follows her. Usagi resolves to apologize to Chibi-Usa, but stops when she hears Chibi-Usa crying. Usagi hides and listens. Chibi-Usa then attempts to communicate to Puu through Luna-P. She says she is scared and wants to go home; that she has no one to help her here. Puu says she is wrong; she has Sailor Moon and the Sailor Senshi. Chibi-Usa exclaims that the Black Moon Clan is stronger; that her dad couldn't even stop them. "Look at what they did to Mama!" she cries. Puu tells her about the Warriors in Crystal Tokyo who watch over her and the city. She says that these same Warriors are in this past world, protecting her and watching over her here, and that she has to believe in them. Then, Puu's connection cuts out. Usagi wonders who Chibi-Usa is talking to, but then realizes that the Black Moon Clan got to Chibi-Usa's mom. She resolves to do whatever she can to protect Chibi-Usa.
Then, Koan appears in front of Chibi-Usa. Usagi transforms. Koan is about to attack Chibi-Usa when Sailor Moon appears and gives her speech. She then kneels down in front of Chibi-Usa. The rest of the Phantom Sisters appear beside Koan and introduce themselves according to age (Petz, Calaveras, Berthier, Koan). The say they are from the tenth planet, the Black Moon. The rest of the Sailor Senshi arrive and introduce themselves in order of appearance (Mercury, Mars, Jupiter, Venus) just as the Sisters are about to attack Sailor Moon and Chibi-Usa.
A battle between the Senshi and the Sisters ensues while Sailor Moon stands back and watches over Chibi-Usa. Each Sister goes up against the Senshi with the corresponding element (Koan/Mars/Fire, Berthier/Mercury/Water, Calaveras/Venus/Chains, Petz/Jupiter/Thunder). Suddenly, dark energy bombs rain down on Sailor Moon and Chibi-Usa. Rubeus has arrived and introduces himself. He proclaims that they are taking over the future city of Crystal Tokyo. And to do so, Chibi-Usa must die. He proceeds to throw more bombs at them, throwing Sailor Moon into the wall. Chibi-Usa cries and screams for Sailor Moon to get up as Rubeus walks over to deliver the final blow. Tuxedo Mask and his rose appear, and he attacks to offset Rubeus's final launch of bombs. He then says that Sailor Moon is the only one who can protect Chibi-Usa. Sailor Moon uses her Moon Princess Elimination attack. Rubeus and the Sisters retreat.
After the battle, Sailor Moon asks Chibi-Usa to tell her the truth about everything. She asks if Chibi-Usa came from the future, and if the Black Moon Clan captured her mother. Chibi-Usa cries and runs into Sailor Moon's arms, asking her and the other Sailor Senshi to save her mother.
Back at Black Moon headquaters, Wiseman is shown glancing at a holographic image of Chibi-Usa's mother while laughing to himself and pronouncing that the Sailor Senshi will go down in the end.
Character Appearances: Chibi-Usa, Shingo, Luna, Artemis, Usagi/Sailor Moon, Rei/Mars, Ami/Mercury, Makoto/Jupiter, Minako/Venus, Tuxedo Mask, Koan, Berther, Calaveras, Petz, Rubeus, Wiseman, Puu/Pluto
Attacks/Items Used: Chibi-Usa's time key, Luna-P, Sailor Moon's Moon Princess Elimination
Villain of the Day: None
Noteworthy Items: Usagi dreams of marrying Mamoru
Quote: "You're precocious, you like to play pranks, and you can be a horrid kid, but....In truth, I will protect this child no matter what!" -- Sailor Moon