Gakkou no kaidan: Noroi no kotodama (2014) Online
Ayano, Yuri, Miyu and Mei are high school female students victims of paranormal incidents that may be linked to a gas accident occurred to first-year students in class number 4, years ago.
Kotodama literally means "the spirit of language" or "the power of words" and refers to the Japanese belief that mystical powers dwell in words.
Japanese don't like number 4 because of its pronunciation. Four is pronounced "shi" which is the same pronunciation as death.
Fear of the number four is known as tetraphobia.