Machigatteita no wa Ore Datta n da.  

I Was Wrong, 間違っていたのは俺だったんだ。

Sara's yandere girlfriend Furuya has finally escaped from her. Although it was easy for him to do so by killing her, she remains as a ghost due to regret. Previously, Furuya felt her presence everywhere when she was alive. Now that she is a spirit, she behaves like any normal girl. It seems that he may have misunderstood her entirely. As his guilt grows, Furuya feels the need to make amends for what he has done, but at what expense?