Chibi-Usa is starting her first day of fourth grade. The other kids are amazed that she has pink hair. She's told to sit next to Momohara Momoko, a little girl wearing a Chinese-style dress. Momo welcomes her, but the boy behind them makes fun of Chibi-Usa: "You've got a big head and you're tiny. I think that's what I'll call you. Tiny! Tiiiiiiny!"
Momo turns around and yells at the boy, whose name is Sarashina Kyusuke, the little brother of Kotono from T*A. Chibi-Usa notices that Kyusuke is wearing a Sailor V badge that his sister made for him. Kyusuke says that heard that there were two girls named Usagi living at the Tsukino house. Momo asks what they usually call Chibi-Usa at home. Chibi-Usa tells her, but adds that she is not chibi. However, Momo thinks it's cute and the name sticks.
During the day, Momo tells Chibi-Usa about Lyrica, a new transfer student. The class geek Sorano adds that Lyrica is the daughter of the U Country ambassador and she lives at the embassy. Lyrica, a pretty blonde girl, doubles over in pain and asks a boy to walk her home.
After school, Ikuko-mama asks Chibi-Usa how her day went. Usagi is only concerned with what name she registered under. Of course, Chibi-Usa registered under "Tsukino Usagi," which sends Usagi into a tantrum. Usagi also gets upset when she learns that no one was wearing a Sailor Moon badge. Kenji-papa tells Chibi-Usa that the U Country embassy is a ghost house.
At school the next day, the boy who walked Lyrica home is absent.
Chibi-Usa and Momo walk by a garden. The garden is so dry, the flowers have to watered everyday. Lyrica sees them and steps up to Chibi-Usa. "Your cheeks are nice and rosy," she tells Chibi-Usa. "Looks delicious." After that, Lyrica goes home early with another boy.
The next day, the second boy who walked Lyrica homes goes missing as well.
Lyrica is missing at lunchtime. Chibi-Usa and Kyusuke are sent outside to look for her. They see her in the garden eating the flowers.
That night, the girls are over Usagi's house, listening to Chibi-Usa's story. Makoto comes to the conclusion that Lyrica must be a vampire. Ami explains that vampires are creatures that drink human blood and love pretty flowers. Makoto takes the chocolate cigarette out of her mouth and says that Lyrica must be luring the boys home and then sucking their blood. Usagi gets scared.
In order to help Chibi-Usa find out if Lyrica really is a vampire, Makoto says that she'll put a lot of garlic in their food. If Lyrica reacts to Chibi-Usa's garlic breath, then they'll know she's a vampire. Rei says that the only way to get rid of a vampire is to drive a wooden stake through its heart. Usagi gets scared again.
When Lyrica doesn't show up for school, the teacher sends Chibi-Usa, Momo, Kyusuke, and Sorano to her house to give her the homework. The embassy is a large house with many flowers and graves in the garden. As the children are looking around, a woman comes up to them. She says that she is Lyrica's mother. Lyrica is sleeping, but she invites the children inside. Chibi-Usa speaks, and garlic fumes come out of her mouth. The woman takes a step back.
Inside, the woman tells them that Lyrica was eating candy flowers. Satisfied that Lyrica is a normal girl, they give the woman her homework and leave. Once outside, Chibi-Usa notices that Momo is missing. When she goes back inside to look for her, the woman bares her fangs and bites Momo's neck. Lyrica rises from one of the coffins: "I'm thirsty... I want blood!"
The boys who went missing also rise from coffins and advance on the children. Just as Lyrica is about to grab Chibi-Usa....
"Crescent Boomerang!"
Sailor V and Sailor Moon appear. They launch themselves at the vampire woman. "Double Sailor Kick!"
Chibi-Usa turns on Lyrica and opens her mouth. "Garlic Attack!" Her breath makes Lyrica fall to the ground. Sailor Moon finishes her off with a Moon Princess Halation. Lyrica shrivels up and becomes a flower.
In her diary that night, Chibi-Usa draws herself as a tiny Sailor Senshi with a cape. She calls herself Sailor Chibi-Usa Moon.
The next day, Kyusuke presents Chibi-Usa with a Sailor Moon badge. "It wasn't a dream," he tells her.
"Right!" The Sailor V badge winks. "It wasn't a dream."
The Sailor Moon badge says, "Sailor V, thanks for the help!"