Kazuki Hoshino clings desperately to the comfort of routine, unaware that his world is about to shatter. When Aya Otonashi transfers into his class for the 13,118th time, she arrives with a singular mission: to destroy him. Indifferent to the chaos she creates, Aya sets in motion a descent into darkness that tears both of them apart from within, fractures their bonds with those around them, and challenges forces that may transcend human understanding. As their twisted dynamic unfolds, Kazuki and Aya find themselves compromising their deepest principles in a war against fate itself, with their connection evolving into something far more complex and dangerous.