Meimi Haneoka, a 14 year old girl, goes to a catholic Junior high school. Her best friend is Seira Mimori a sister in training. Asuka Jr. is the son of a detective and plans to be a detective himself. Meimi and Asuka always argue and do not get along. Meimi is secretly Saint Tail. A mysterious thief who always steals for good reason.
A little girl goes to the church where Seira is a sister in training and tells Seira that her father, an appraiser, stole The Blue Meteor from and employer, Kaido, and gave him a fake stone instead. He did this in a moment of weakness and now regrets his actions.That night, Meimi goes to the Kaido residence as Saint Tail to switch the fake stone for the real one. Asuka Jr. is there to guard the Jewel, hired by Kaido. Saint Tail distracts the rest of the guards with magic shadows so that only Asuka Jr. and she are in the room. She gets the fake jewel but forgets to replace it with the real one, so she leaps from the window ledge to return the real stone. She crashes into Asuka Jr. and has to spray him with sleeping cologne to keep her identity a secret. She slips the real jewel in Asuka Jr's hand and disappears, so he is given credit for saving the Blue Meteor.
Asuka Jr. Is asked by the mayor to capture Saint Tail because he is the only one who has seen her up close and "stopped" her from stealing the last time. Meimi is furious because everyone is saying Saint Tail failed so she sends Asuka Jr. a huge balloon calling card saying where she is going to strike next.
In the confessional Seira tells Meimi her next job is to retrieve a tiara called electra. The tiara was conned away from it's rightful owner by a man named Egami. Because of the calling card a rumor starts that Asuka Jr. and Meimi are partners in crime. So Egami, who believes the rumors, tells Asuka Jr. that he has hidden the tiara in the short hand in the North clock tower, when it is actually hidden behind the long hand. Egami hopes to capture both Asuka Jr. and Saint tail when Saint tail goes to get it behind the wrong hand.
That night Saint Tail appears and takes the tiara from behind the long hand of the clock tower. This action clears Asuka Jr's name. Egami fires a gun at saint tail while she tries to escape holding on to balloons.
Asuka stops him and she gets away. But not before he challenges her and tells her to always send him a calling card. The next day Meimi has a band-aid on her cheek from the balloon exploding next to her face. Asuka becomes suspicious.
Sayaka Shinomiya, a student at Meimi's school, received a wedding veil from a fiance that she has never met. Sayaka does not want to get married to her fiancé because she likes someone else, Asuka Jr. Meimi gives off small hints that she may be jealous.
Saint Tail writes her calling card on Asuka Jr's face while he is asleep. That evening Saint Tail steals the Wedding Veil from under Asuka's nose. He chases her onto the roof and asks her why she stole the veil, asking is she was just a common thief after all. Meimi tells him, while disappearing into smoke, to ask Sayaka why she stole it and that he was clueless.
The next day Sayaka tells everyone that Saint Tail returned the veil to her excerpt from -fiancé and he was so mad that he broke off the engagement.
Asuka Jr. Is sulking because Saint Tail hasn't appeared in a while so Meimi tries to cheer him up. They get in an argument and he says that Saint Tail is twice the woman Meimi is. Meimi is furious and runs off.
Mayu, a little girl, tells Seira that her pet, Tama, was stolen by the class bully named Goh. Before Meimi leaves to do saint tales work she does not give Asuka Jr. a calling card because she is still mad at him. Saint Tale goes to Goh's house that night and finds Tama, a huge lizard. Afraid to touch it, she levitates the lizard with her magic and returns it to Mayu.
The next morning at School Asuka Jr. is upset because he didn't get a calling card. Meimi and he fight and she tells him he will never catch saint tail, that he is clueless. Asuka recognizes the phrase and Meimi is terrified that Asuka Jr. has figured out that she is Saint Tail.
That night Asuka Jr. goes on the news and tells Saint Tail to meet him at the park of he will reveal her identity. Meimi meets Seira at the church and her friend tells her that Asuka Jr. may be bluffing so she must not reveal herself. Meimi says that if she has to be captured then she wants to be captured by Asuka Jr.
Asuka Jr. waits in a phone booth and speaks to Saint Tail via his cell phone he left outside. He was bluffing about knowing her identity and brought her there to ask why he didn't get a calling card. He says it wouldn't be right if she was caught by anyone else.
Meimi, obviously touched, goes down to the phone booth but Asuka can not see her because the windows are fogged up by snow. Meimi apologizes for braking her promise to send a calling card and says she won't do it again. Asuka Jr. Makes her promise that she won't let anyone else catch her before he does.
Before class starts Meimi and her friends talk about a new amusement park, Wonder Garden. They talk about the Wonder Garden Castle that has expensive clock work doll. It's said if you watch the clock as a couple, you'll be happy together. The girls tease Meimi that she might want to go on a date with Asuka Jr. to the park and her and Asuka Jr. get in a fight.
After school in the church Seira speaks to a troubled mother and her daughter, who had gone to the park. The little girl, Eri had borrowed a cherished doll from her cousin and had lost it at the park. Eri had tied to the dolls hand to her balloon and it had floated away and was stuck atop the Wonder Garden Castle. Seira relates this to Meimi later in the confessional.
Asuka Jr. gets a calling card from Saint Tail on the back of a flyer for Wonder Garden, saying that Saint Tail will go for the doll at Wonder Garden. Asuka Jr. goes to Meimi and asks her about the park. Meimi thinks he may be asking her on a date and gets excited. But he only wanted know if the clock work dolls at the park where worth a lot of money. Meimi gets mad and screams,"I HATE YOU!"
The next night Meimi's parents go to her room and she is missing. They don't think much of it. Saying she's just like her mother to disappear by climbing out of her window. (Her mother the former thief.) Saint tail appears on the roof of the castle gets the child's doll. She notices that there is no one around. Suddenly flood lights go on and focus on Saint Tail. Saint Tail creates a light show in the air for a distraction then she created a parade of Saint Tail illusions. She planned to escape in the confusion but Asuka Jr. ran after her as if he knew who was illusion and who was real.
He chases her into a Ferris wheel car where he sees the doll that she was really after. Meimi thinks as she looks at Asuka that she would have liked it if he had asked her out. She shock him by saying "It's been fun! Just like a date!" While Asuka is busy blushing and trying not to fall out of the car Saint Tail disappears in a flash of light. Asuka Jr. is commended by the park owner because they believe he kept the clock work dolls safe. Asuka, confused about Saint tail stealing a child's toy, does not correct them.
Seira speaks to an older man and later in the confessional tells Meimi his story. He signed a contract with a museum that he though promised the lending of his famous painting, Cherry blossoms, but the museum switched it with a contract saying he contributed it. Meimi promises Saint Tail will take care of it.
At the arcade Asuka Jr. plays a video when an obnoxious girl starts telling him to play it differently then pushes him out of the way so she can play it for him. The screen flashes GAME OVER, Asuka Jr. is kept from yelling at the girl when a calling card from Saint Tail flashes on the video screen. It says she will go for the painting "Cherry Blossoms" tomorrow night.
The girl introduces herself as Lina Takamiya, 14 years old and new in town. Asuka is embarrassed to note he is shorter than her. Lina seems very interested in Saint Tail and the calling card.
Meimi changes into Saint Tail at the church and Seira tells Meimi to be careful because she feels something different is going to start. At the museum Asuka waits for Saint Tail when a guard comes in with Lina. She says she is there to protect her paintings that her family has loaned to the museum. Before Asuka Jr. can argue the lights go out and when they come back on the painting is gone.
Lina and Asuka race each other as they follow the trail of cherry blossom petals out of the room; the guards follow. Alone in the room, hanging from the ceiling, Saint Tail goes down to the floor. She does a magic trick and the illusion that made it look like Cherry Blossoms was gone, disappeared.
Lina and Asuka Jr. follow the pedals into a janitors closet then go outside after Lina tells Asuka jr that she made up the story about her family donating painting, thinking he's an idiot for believing her.
Outside Saint Tail stand atop a towering sculpture. She tells Asuka Jr. he did a good job then disappears in a great wind whirl. Lina boasts she could have caught the thief if Asuka Jr hadn't been in her way.
The next day at school Meimi is asked to show a new student to their class room. She is shocked to recognize Lina as the new student. Lina tells Meimi she wants to find someone called Asuka Jr. Meimi freezes in shock.
Meimi wonders what Lina could want with Asuka Jr. In the class room Lina hugs Asuka Jr. real tight and says she's been looking for him since last night. Lina continues to flirt while throwing in little insults. (Like about his short height.) Asuka Jr. gets annoyed. Lina says she's going to be a woman police officer. So all criminals are her enemy, especially Saint Tail. Asuka Jr. and Lina argue about who is going to catch Saint Tail and she tells them that the mayor is her uncle. During this Meimi is looking very angry and maybe a little jealous. Meimi storms off saying how dare Lina cling to him!
In the church Seira consuls a young man. He is a sculptor and made a replica of the "Yato dagger" that is being displayed at the F Center. He made it on the terms that the dagger would be enjoyed in a private home. He is over come with guilt knowing that the fake is being displayed as the real thing.
Seira tells Meimi in the confessional later on and Meimi seems very determined. At lunch Asuka Jr. gets a calling car from Saint Tail in his lunch and everyone fights to eat a piece of it.
That night Asuka Jr. guards the dagger, it is in a special room in the shape of a pyramid. Asuka Jr. put a guard at the door and will hide in a sarcophagus in the room. Lina shows up with a letter from the mayor telling Asuka Jr. to let her help capture Saint Tail. She tells him the plan he has will fail but waits in the monitoring room.
Saint Tail slips into the pyramid room easily and Asuka Jr. waits for her. She disables all the security cameras with playing cards and goes for the dagger. Asuka jumps out and is about to grab Saint Tail when Lina shoots some kind of gas into the room. Lina was angry because the cameras had all stopped working so decided to take charge.
Saint Tail falls to her knees coughing and Asuka Jr suddenly wraps her in his arms. He tells her to try not to breath. Meimi can't bring herself to pull away from him to get away and protect her identity. Asuka is surprise she does not run. He pulls away to look at her face but the gas is tear gas and he can not see through the tears. Lina rushes in and sees Asuka holding onto Saint Tail and punches him. Angry, Asuka lets go of Saint Tail to yell at Lina. Saint Tail gets the Dagger and gets away.
The next day at school Asuka explains to Lina that Saint Tail knew the dagger was a fake and that she helped someone. (It came out in the paper the next day.) Meimi passes Asuka Jr. and comments that he was crying last night. Asuka asked her how she knows and she says his eyes are red. He won't tell her why thought and walks off. Meimi smiles after him and thinks she knows, because he always does his best and he's nice.
Asuka Jr. and Lina chase after Saint tail but it's took late, she's gotten away floating on a huge balloon. Lina catches two baseball tickets that fall from the sky. She wonders if they are Saint Tail's.
In the church pitcher Oikawa of the Kohnan Dolphins Seira that his favorite glove was stolen by the a little girl named Uehara. She had asked him for an autograph and he had handed her his glove to hold while he signing her car. When he looked up she and the glove were gone. He does not want to get her in trouble and hopes she will return it on her own.
In the confessional Meimi hears the story and says she's planning to go to his the Dolphin's next game. Then she realizes she lost her tickets but doesn't know where. She bought them because Asuka Jr. had only promised to help her study for math if she bought the tickets. Seira says it's a date but Meimi blushes and says it's bribery.
When Meimi asks around class if anyone has seen her lost baseball tickets, Lina over hears. She becomes suspicious. Lina watches Meimi and becomes more sure that she is Saint Tail. Asuka Jr. gets a calling card from an exploded soccer ball. Lina asks Meimi to go outside with her so they can talk. She shows Meimi the tickets she found and tells her where she found them. Meimi says they are not her's (Even though they are.) because she knows Lina suspects her to be Saint Tail.
Asuka Jr. takes Uehara to the Big Dome Baseball field to wait for Saint Tail, if she can find them. Seira told Saint Tail where Asuka Jr. and the glove would be so she went there and over heard Lina and Asuka Jr. talking. Lina asks Asuka Jr. to the baseball game. Asuka declines, saying he is going with Meimi already. Then Lina says she knows who saint Tail is and will tell him if he goes with her to the game. Asuka becomes angry, saying he just wants to catch her on his own, it doesn't matter who she is.
The dome's roof opens and Saint Tail floats down sitting on a huge balloon. She levitates Uehara and Lina until the little girl says she's sorry. Meimi takes the gloves and her lost tickets from Lina. She tells Uehara she can't steal things no matter how big a fan she is. Asuka Jr. hadn't known the glove was stolen and was surprised. As Saint Tail floats away holding on to her big balloon she thinks to Asuka Jr. "Thank you. I love you...."
The next day at school Asuka Jr. argue about where to meet at the baseball game and Lina becomes more determined to prove Meimi is Saint Tail. At the game Asuka Jr and Meimi sit next to each other. Asuka says it's been such a good game because of Saint tail, Meimi blushes. He asks her why she's blushing and tells him it's none of his business. She thinks "I love you." and makes up the excuse that it's hot out there.
A class mate of Meimi and Seira goes to the church, her name is Miki. She tells Seira that her design sketch of a wedding dress was stolen. She is going to use the design in an upcoming contest that she asked Meimi to model her dress in. Miki thinks that Mami from class E stole her design because she is in the contest too and thinks of Miki as a rival.
Lina follows Meimi around and Meimi finally looses her and goes to the church. Seira tells her about Miki's problem in the confessional. Meimi isn't sure she can help because Lina is following her so closely. Seira says that she will take care of it. Lina continues to ask Asuka Jr if he wants to know who Saint Tail is and he tells her he doesn't care. Asuka Jr. gets a calling card that hangs in the hall next to a poster for the wedding dress contest.
At the contest Lina tells Asuka she will reveal who Saint Tail is. Asuka stays with Mami to protect her, Mami clings to her design. Lina goes to the dressing room where Meimi, Seira and Miki are and stays close until she gets kicked out because she's not aloud in. But she stays right by the door, watching Meimi. As soon as the dressing room is empty Seira and Meimi go into the dressing room and Meimi transforms in to Saint Tail. Seira puts on the wedding dress and a "Meimi" wig.
While Lina is distracted Saint Tail sneaks out of the dressing room and Seira stays inside, looking like Meimi. Suddenly Mami's design floats away from her grip and Saint Tail takes it. She replaced the wedding dress that Mami's girl is wearing with a lizard suit. Saint Tail says she will return the design and dress to the original owner. Asuka Jr. doesn't move to stop Saint Tail because he asks Mami if the design was stolen. Saint Tail makes bouquets shower down to all the girl as a way to make up for interrupting the contest then disappears.
Lina and Asuka Jr. see what looks like Saint Tail floating away on a huge balloon. But really Seira had set it look with a Saint Tail looking balloon hanging on to it. When Lina runs into the dressing room, Meimi stands with Seira and Miki wearing the wedding dress. Miki's dress wins the contest. Lina asks Asuka Jr. what is Meimi is Saint Tail. Asuka says he doesn't believe her. They make a bet, if Meimi isn't Saint Tail then Lina will leave Meimi alone, but if she is Saint Tail then Asuka Jr. Will go out with Lina.
At school Meimi over hears Lina pestering Asuka Jr. reminding him of their bet. Meimi asks Lina what the bet is about and Lina tells her is she can prove that Meimi is Saint Tail then Asuka will go out with her. Meimi appears to be shocked and goes to the church telling Seira about the bet. Meimi says that now that there is a bet she can't let Asuka Jr. capture her. Seira asks if she wants to be captured and Meimi screams N-N-N-NO WAY!
In the confessional Seira tells Meimi of another lost lamb, a young man named Mr. Kanamori. His grandfather passed away and his relatives had the will changed so he did not receive an important gem that is a family heirloom. His relatives are going to sell it but Mr. Kanamori is trying to get it back before they can.
Meimi hesitates to accept this new mission because of the bet and Lina watching her so closely. Seira reassure her and says that she will take care of it. Seira says that they will use the rumor that Saint Tail is a girl.
Asuka Jr. gets a calling card that falls out of an egg while he's cooking breakfast. Lina reads the card and says they will use Saint Tails weak spot to catch her. Asuka is unwilling to play any cowardly tricks so Lina says she will do it without him.
Before Saint Tail leaves the church that night, Seira gives her the sleeping perfume she used to put Asuka Jr. to sleep on their first meeting. All the guards are posted outside the building where the gem is kept, Asuka is outside with them. Saint Tail sneaks down and puts one of the male guards to sleep with the perfume, she says she needs his help.
Inside the building Saint Tail sees Asuka Jr. laying on the ground as if unconscious. Saint Tail goes down to him to see if he's alright when suddenly he moves and grabs her hand. It was Lina pretending to be Asuka Jr. Lina holds on tight to Saint Tail's wrist and yells for Asuka Jr. to turn on the lights. Asuka runs in, angry saying he is going to be the one to capture her. Saint Tail does a quick magic trick and when the lights go on they see a man in a Saint Tail costume. (The guard.) The real Saint Tail grabs the gem and gets on the roof. Lina and Asuka, who think the man in really Saint Tail are in shock. Saint Tail makes the man disappear and gets away with the gem.
Asuka Jr. goes home, he is upset about Saint Tail being a guy and thinks "It's not fair..." A calling card floats onto his head asking him to meet Saint Tail in D park if he promises not to get to close. Asuka Goes and Saint Tail is sitting on top of a large clock that is way overhead. Asuka sees that Saint Tail really is a girl. Saint Tail tells him thats what he gets for ganging up on her with that girl (Lina) and tells him not to reveal her identity again.
Asuka tells Saint Tail about his bet with Lina. Saint Tail tells him is she is going to be captured she wants him to be the one to do it. Then she disappears and Asuka Jr. wonders what she meant by that. He decides not to tell Lina about their meeting.
At school Asuka wins the bet because Lina still thinks Saint Tail is a guy. Meimi asks him what the bet was about and Asuka looks at her oddly and thinks it couldn't be her that is Saint Tail. Not someone so close.
Meimi goes everyday after school to see a little hedgehog in a pet shop window. A man buys it right after Meimi leaves with her friends.
A man named Kamimura goes to Seira at the church and tells her that he has shared ownership of a diamond called Polar Tear with another man named Hayase, for many years. When Kamimura went to Hayase to have his turn with the diamond the other man claimed he already gave him the stone. Kamimura called the police but they could not find the diamond in Hayase's home. So now Hayase is demanding that Kamimura repay him for the loss of the stone.
Meimi hears the story in the confessional and says she's will recover the polar tear. Then she starts to cry saying the hedgehog at the pet store was sold. Asuka gets a calling card in his book and accidentally reads it out loud to the whole class. Lina says she has lost interest in catching Saint Tail and wishes Asuka Jr. good luck. Really she thinks that since Saint Tail is a guy she doesn't' have to worry about losing Asuka to him.
That night Saint Tail stands outside Hayase's window and hears him talking to the hedgehog that he bough, the same one Meimi wanted. Hayase says that the diamond is in the hedgehogs stomach. Saint Tail is outraged. Asuka comes in the room and accidentally lets the hedgehog out of it's cage, and it runs off.
Saint Tail crashes through the window and chases after the hedgehog. It falls onto Asuka Jr.'s head and he runs away from the chasing Hayase. He falls through a trap door Saint Tail set up and gets the hedgehog. Hayase chases after Saint Tail and she goes into an elevator. Hayase and Asuka get into the elevator next to it. When they catch up to her and the elevator door open a huge hedgehog balloon comes out and knocks them down.
Saint Tail pops the balloon and the hedgehog spit out the diamond. Saint Tail tells Hayase thats what he gets for trying to keep the diamond for himself. Saint Tail floats away holding on to a huge balloon and throws Asuka the polar tear telling him he can take care of the rest. Hayase is arrested and Saint Tail keeps the hedgehog.
