This is poetically twisted. Hirota Osamu and Murase Chika, they are each others last bastion or the bond that keeps their monstrous side in check. It may have been a coincidence, but to think that Osamu would hurt her. Inconcivable in her view, betrayed by your loved one. The pain will come back tenfold i believe. Now that she's a broken mess, what Osamu will do in the next chapters is crucial. He strayed further away from his humanity with his conflict with glasses kun, i don't see him going through this with his sanity intact. Miwako, horrible as she is, an amazing villain! Hope she gets her slice of desparity in the end.