Based on the IMDb plot summary and AsianWiki profile , here is an informative guide to the beginning of this dark revenge story:
(Hiroya Shimizu): Another transfer student and Haruka's only friend and emotional support. (Dramacool-SUB) Liverleaf Episode 1
: The bullies' harassment culminates in a horrific act of arson. They set Haruka's house on fire while her family is inside, leading to the death of her parents and leaving her younger sister, Shoko, with severe burns. Based on the IMDb plot summary and AsianWiki
: The homeroom teacher, Kyoko Minami, is portrayed as cowardly and indifferent, refusing to intervene despite the obvious abuse. is portrayed as cowardly and indifferent