Gakkou no Kaidan 3 (1997)

Description:

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.