Galaxia's new henchwomen, Sailor Aluminum Siren and Sailor Lead Crow, take up Sailor Iron Mouse's task. Usagi finds a strange little girl, whom she tries to talk with. The girl, who apparently can only say "Chibi", then runs off. She later appears at Usagi's home, Ikuko Tsukino now declaring her Usagi's sister. After a search for a lost Chibi Chibi, Sailor Aluminum Siren changes a chief of police into a Phage. Usagi and Setsuna now have to face this new enemy.