The story starts in 1997, the janitor turns out to be a teacher, an art teacher, same as the female art teacher. The female art teacher likes him. But he and his student, the girl, have feelings for each other, and the female art teacher is cynical.
Once the girl was so happy after confessing her love to the teacher that she accidentally knocked off the female art teacher's sculpture, and the girl looked so tugged at it that she got a slap on the wrist and a grudge. The girl ran to the drawing room to wait for the male teacher, but the date note was found by the female teacher, the female art teacher was furious and ran to the drawing room smashing things, the gasoline used for oil painting was spilled, and the lights were broken. The girl is scared, but waits as promised and slowly falls asleep in the dark.
The male teacher came back and found that the lights did not work, so he lit a match, surprised at the destruction of the room dropped the match on the floor and ignited the gasoline spilled on the floor, the house was on fire, and the girl was still inside, heard her screams, the male teacher tried desperately to save her, but the girl was dead.
The male teacher thought he had harmed the girl, and was heartbroken and insane, and was disfigured and disabled in the fire, so he turned janitor, but he still remembered the flowers the girl had given him, and the sculpture in the house wearing the girl's uniform, and he fell in love with her, and brushed her hair, and danced with her, and he couldn't forget the girl.
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Five years later (2002), a new female teacher comes to the school, which is actually the girl's spirit. The girl helps the janitor out when he is bullied by the students. She meets her sweetheart, though already the crazy and stupid janitor. The girl's appearance causes a stir among the students and teachers. The handsome teacher also takes a liking to her, but causes jealousy among the girls who have a crush on him.
The girl found the janitor's place after school. She doesn't identify herself and is happy to see that the teacher-turned-cleaner still hasn't forgotten her, reveling in the memories of her past. The handsome teacher who came after her didn't know all this and fell in love with her.
The female art teacher has moved on by this time and likes the handsome male teacher, but by chance she sees that the new female teacher looks exactly like the girl and breaks the sculpture in her hand in shock.
The cleaner saw the new teacher as a girl and gave her a bottle of flowers like the old one, and the male teacher also sent flowers to the female teacher (obviously lacking taste), the new teacher had to respond to the cleaner's misunderstanding of the girl's preference for the handsome teacher.
The female art teacher overhears the handsome teacher making a pass at the girl, and she feels that the new female teacher, like the girl before, is her sworn enemy, and wants to take everything away from her.
Obviously the girl likes her old lover's little vase, and on a rainy night she takes it with her to try to get home, and the handsome teacher wants to give her a ride, and accidentally (or is it on purpose?) smashes the vase, which the female art teacher bumps into, and assumes that the two of them are making progress, adding to their hatred.
One night, when the cleaner was on night patrol, she bumped into the girl flipping through her photo album, looking for memories. The cleaner thought that the teacher was doing it on purpose and left in anger. The male teacher asks the girl to go up to the rooftop, confesses his love to her, gives her a ring, and kisses her when the janitor and the female art teacher see him. Handsome teacher was rejected, angry back to the office, in the office found a book, which is the girl died 5 years ago and the cleaner's files and photos, next to the female teacher's photo, he looked at it and realized that the female teacher and the year the dead girl looks like, understand something, and was very nervous to run to the rooftop of the school to look for the girl.
And at that moment, the female art teacher and the girl were confronting each other. The female art teacher slapped the girl again, the girl was furious, and the two wrestled.
The girl couldn't stand up to the female art teacher, and was choked and fainted. The female art teacher thought she had killed someone and rushed away. Perhaps she wanted to make it clear to others that the female art teacher was the one who started it, when the handsome teacher just arrived and the janitor was present, but froze and didn't save her right away.
The girl, utterly disappointed in her lover, climbed the barricade, closed her eyes and fell.
The cleaner returns to consciousness but is devastated by what he has done, but the girl is dead.
The female art teacher flees in panic, and the handsome teacher, at a loss for words, believes the fact that the girl is a spirit.
The girl's body is found by a girl who has a crush on Mr. Handsome and becomes the scapegoat (love murder) according to the students. She in turn sees Mr. Handsome and the female art teacher snuggling at the new female teacher's funeral and realizes that she will never be seen by Mr. Handsome, eventually leading her to hang herself at the school.
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(The girl's spirit is still there, wearing a red dress and curly hair, but her face is expressionless.)
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Five years later (2007), the female art teacher is finally with the male teacher, and the janitor still works at the school, unidentified. A woman comes in at the school entrance and looks back at the female art teacher . The female teacher freezes,Handsome Teacher, and the janitor is hooked into the memories as the woman removes her sunglasses and reveals a wry smile. Because she (the girl in 97 - the new female teacher in 2002) is back.