Dissolving Classroom (2017)

English translation of the Japanese manga Youkai Kyoushitsu (溶解教室).
A pair of twisted siblings-Yuuma, a young man obsessed with the devil, and Chizumi, the worst little sister in recorded history-cause all sorts of tragic and terrifying things to happen wherever they go. These scary short stories will shock you with a literal interpretation of the ills that plague modern society.