Kurohane attempts the same with her mother but proves to no effect, so she enters a competition to improve her skills.

Her school life did not go so well because her classmates led by class president Sonada Shiori were mean to her, and often became a victim of their cruel bullying.

She killed people randomly, so Yuka wrote a short story with Kurohane's words in it and posted it online, increasing her time to live.

Author Yuka Hidaka originally published the story online on the website Maho no iLand in 2011 as a cell phone novel.

[2] ASCII Media Works announced in a press release on July 11, 2011 that the novel would receive a live-action adaptation starring the members of the Japanese idol girl group Buono!, consisting of Momoko Tsugunaga, Miyabi Natsuyaki, and Airi Suzuki, in their debut starring film.

[6] Mark Schilling from The Japan Times described the beginning of the film with a "standard issue 'bully the strange girl in class' story line", but mentioned that it takes a "scarily fresh turn" when the bullied character takes revenge on her classmates.