The infamous Hinamizawa series of incomprehensible killings have been solved, and the links of fate have been broken, thanks to the efforts of Rika Furude and her companions. Rika feels she has finally achieved the typical and quiet life she craved with her friends; however, she is proven incorrect as the wheels of fate begin to revolve once more following a tragic event. Rika finds herself in a "perfect" world, where the continual cycle of horrible killings has never occurred, and all of her friends are comfortable and fulfilled. She discovers that in order to return to the world she worked so hard for, she must destroy a crucial "key." But can Rika be able to leave the immaculate world she is given the opportunity to leave?