Believing Black Moon may have taken the other Sailor Guardians to the future, Usagi and Minako asks Chibi-Usa if they can take them to the future, but Mamoru suggests they give her some time to think it over first. As Chibi-Usa spends the night at Mamoru's apartment. Usagi admits get jealousy over how close the two appear to be, but Mamoru gives her his assurance and spends the night with her. Meanwhile, Luna recalls in a dream about a closed for in the Moon Kingdom that Queen Serenity forbid her from opening. The next day, Chibi-Usa decides to take Usagi and the others to the future, using her space-time key to open up. However, they become separated from Chibi-Usa and winds up across the door from Luna's dream, which is guarded by the Guardian of Time, Sailor Pluto. Believing Usagi and the others to be intruders, Pluto is hostile towards them until she is stopped by Chibi-Usa, who is revealed to be a princess. Glad to see Chibi-Usa's safe return, Pluto grants the group passage to ...