Grudge Girls Academy: Serial Murder of Fear! 1981

There are two bizarre rumors spreading about a girls' high school called “Seiwa Joshi Gakuen.” The first is a “Hanako-san in the Toilet”-like story about a painting that hangs in the principal's office = young twin sisters who escape from the painting at night and promenade around the school. The other is about Ryoko Mizumura, an art teacher who is too beautiful to be true and the object of the students' admiration, but who may actually be two people.