A literally wild ride has come to an end. I mean im her own twisted way Mitsuko thought fucking him would make Yuichiro feel better, not seeing that it made him feel even more pain. Ironically in contrast to her line from when she killed her friend, she truly didn't understand this time. She felt disappointed by his words and killed him. I don't really symphatize with her nor do I think she's super evil. She's just a broken doll. One that's destryoing everything around her.
Yuichiro still died like a Chad.