Sekibanki is a rokurokubi, a famous type of youkai. Though she is rather cynical, she has enough self-control that she can live among humans in the Human Village. While she had once gone on a rampage near the village during an incident, now she lives her life quietly.

There are two types of rokurokubi: ones with extendable necks and ones with detachable heads. The latter is said to be similar to the Chinese youkai called hitouban.

Rokurokubi look like regular humans in the daytime, but when they sleep at night, either their necks extend or their heads become detached. This happens when their souls leave their bodies, like when someone goes into a trance. Some scholars thought it was related to sleepwalking.

Ireland has a legend of a headless knight called the Dullahan. The Dullahan is said to be a horse rider with reins in one hand and their own head in the other, and is considered the ruler of death.

Taira no Masakado was a samurai famous for leading a rebellion against the central Kyoto government in the Heian period. When he was beheaded, it is said that his head did not rot and continued to curse even after it was cut off. According to legend, his head then flew off in search of its body.