Susanoo-no-Mikoto is known as the weeping god in Japanese mythology. In Japanese mythology, Susanoo is the storm god. After being exiled from Heaven, he ended up near a river in Izumo Province. He heard crying and found a family of earthly gods. Susanoo is the younger brother of the sun goddess Amaterasu. He is also known as Susanoo no Mikoto, which translates to "Impetuous Male".
The Jubokko (Japanese: 樹木子, "tree child") is a yōkai tree in Japanese folklore that appears in many books related to Japanese yōkai, including Shigeru Mizuki's works. According to folklore, it appears in former battlefields where many people have died, and its appearance does not differ that much from ordinary trees. Since it becomes a yōkai tree by sucking up large quantities of blood from the dead, it lives on human blood. When a human being happens to pass by, it supposedly captures the victim and, changing its branches into the shape of a tube, sucks the blood out of the victim. A Jubokko that sucks life out of human beings in such a way is said to always maintain a fresh appearance. When a Jubokko is cut, blood trickles out. It is said that a Jubokko branch could heal and decontaminate an injured person
The song is a reference to the Japanese Onibi. Onibi (鬼火, "Demon Fire") is a type of atmospheric ghost light in legends of Japan. According to folklore, they are the spirits born from the corpses of humans and animals. They are also said to be resentful people who have become fire and appeared. Also, sometimes the words "will-o'-wisp" or "jack-o'-lantern" are translated into Japanese as "onibi". According to the Wakan Sansai Zue written in the Edo period, it was a blue light like a pine torchlight, and several oni bi would gather together, and humans who come close would have their spirit sucked out.