Third installment of the "Gakko No Kaidan" series follows the trek of several elementary school students as they wander into an alternate world that exists on the opposite side of a school mirror. Nishida Naomi (the hapless teacher in "Gakko No Kaidan 2") returns as the teacher who accompanies the children on their journey into the surreal universe.

Schoolgirls on the verge of adulthood know that boys can be feckless and girls treacherous. Three friends gather around a Ouija board to call forth the spirit of Kokkuri. Masami has a boyfriend, Akira; Hiroko, who is nervous about the séance, wonders if she should take the plunge into sex; Mio is haunted by her mother's suicide. She also has a secret life as the voice of a midnight talk show host, the sexually-charged Midori. Mio must explore her past and her new feelings. Can she hold off the power and predictions of Kokkuri to enter adulthood, or will the destructive and romantic side of teen spirit be too powerful?