After Kurusu Kimihito went on a date with M.O.N(Tionshina,Zombina, and Manako), he saw a mysterious woman in the middle of the road. As Kimihito took her home, It was revealed that she was D. D managed to lose her head, so everybody decided to help look for her. After finding her, she introduced herself as a Dullahan, a reaper of souls. After bringing her home, they had a conversation, regarding why she sent that letter to Kimihito. It turns out, that letter was a warning, because Kimihito is on the brink of death.