Mutsukabezaka

Mutsukabezaka (六壁坂) is a creature appearing only in the one-shot Thus Spoke Rohan Kishibe - Episode 2: Mutsu-kabe Hill.

Personality
Mutsukabezaka is a malignnant supernatural creature. It possesses people and makes them suffer with the feeling of losing someone just because it feels happy.

It also makes humans do everything when possessing them, so the yokai doesn't need any responsibility. It also holds the characteristic of bleeding forever after dying, no matter what its done to stop it.

History
According to Rohan Kishibe's research, Mutsukabezaka is a Yokai from possibly thousands of years ago. Ever since then it has been possessing people's love and the weakness of their heart, making humans do all the work while not having any labor or responsibility itself. Its only purpose is leaving descendants. The peak of happiness for this creature is when they die in front of somebody, at which point they posses the witness while making its previous host bleed forever. The few Mutsukabezaka yokais left on Earth are somewhere, dying in front of someone on purpose. Gunpei Kamafusa was possessed by one Mutsukabezaka, who made him die in front of his lover and impregnated her with its descendants.

Mutsu-kabe Hill
After learning about Gunpei's story, Rohan investigates the region around Naoko Osato's house to discover his goal, suspecting him to be a yokai. Rohan comes across a young girl, who him she's not allowed to talk to strangers and runs away. Rohan tries to catch her, but she ends up falling on the ground and hitting her head on a rock, bleeding just like Gunpei did when he died. Rohan realizes this girl is actually Osato's daughter with Kamafusa, surprised the man who became a corpse was able to impregnate her while being dead. Rohan soon realizes the girl is possessed by a yokai, which just died in order to posses him, and uses Heaven's Door to write one last memory before the girl dies and the yokai transfers to him: "I don't know Rohan Kishibe. Even if I meet him, I won't see him". The yokai briefly shows its true form in order to posses Rohan, but stops its attack and returns back to the girl's body after being unable to see him. The girl, still alive due to the yokai's return, leaves the area, while Rohan comments to himself that one second late and he would have been possessed or exterminated by the yokai. He names the yokai Mutsukabezaka and declares his research complete.