Ishikui, literally translated as “Stone-Eater,” is a fearsome hundred-year-old yokai encountered by Ushio when two of his best friends (and strongest romantic interests) encounter a stone statue of samurai armor in an old wing of the school, intended to be used during history class by their professor. Unknown to both the students and the faculty, inside the statue is a disgusting, two-headed centipede that preys on humans.

The Ishikui isolates its victims by creating an impenetrable illusion that allows it to take its time instilling fear in the hearts of those it preys on. Like a normal Japanese centipede, its venom is toxic and causes paralysis, although, in this case, it turns its victims into stone, before eating them from the inside! It is definitely a creature not to be underestimated.

Michio Hanyuu was a renowned artist with nothing but love in his heart for his wife, and his precious daughter, Reiko. However, everything changed when his wife cheated on him and abandoned both of them, causing his pure heart to twist into something darker. He was gripped by a fervor in creating his last painting, so driven by hatred that his soul was transferred into the artwork itself, and transformed into the fearsome demon, Oni.

As a hate-filled demon, Oni made it his mission to keep that which was most precious to him in life; his daughter. However, his obsession leads to her isolation, as mysterious accidents befell anyone that managed to grow close to her, and the depressing reality of her existence has caused her to attempt suicide time and again. With no hope left, is there any way Ushio can rescue her from the painting-dwelling demon?

The Gamin are an ancient group of five yokai embodied as man-eating floating heads. Originally from the Asian mainland, they settled in Japan, where there was plenty of villagers for them to prey on, and wreaked havoc in a remote village. However, they were eventually sealed and buried through the efforts of the powerful priestess, Hizaki Mikado.

However, when a present-day construction project unearths the seal, the construction crew inadvertently releases the Gamin, who immediately leave a bloody swath of destruction and bodies in their wake. With a grudge against the Mikado, the Gamin hunger for the blood of the Mikado, but are more than willing to settle for that of her ancestor’s, Ushio’s classmate, the soft-spoken Mayuko.

Not all yokai in Japan are malevolent, as proven by a former acquaintance of Tora’s, Umizatō. His appearance is that of a feeble old man with a penchant for sake, unable to move without the help of his walking stick. However, there’s more to him than meets the eye-this old man is the guardian of the ocean and all the beasts that dwell within.

Although he is powerful in his own right, when the giant sea-serpent made up of the souls of the deceased, Ayazako, awakens, he is forced to request help from Ushio and Tora to help send the beast back to the depths and reclaim his domain.

After a mysterious incident causes an air carrier for the Japanese Self-Defense Force to crash and the death of all of its 200 occupants, young girl Yū searches for clues of what lead to her father’s death. While initially, she believed it to be the work of one of her father’s jealous co-workers, it is actually due to the cruel machinations of the air-born yokai, Fusuma.

Like many beasts on the list, Fusuma feeds on humans, and the advent of airlines has provided it with plenty of easy, sky-bound prey. When the flight his is on is beset by the grotesque, wind-based creature, it is up to the power bestowed by the Beast Spear to put Fusuma to rest.

Another pair of yokai who bear humans no ill-will, Tokisaka and Tokijun are strange, twin creatures capable of manipulating time itself. While this fantastic power isn’t without its limits, it could be used for great harm in the hands of a more malevolent spirit.

Fortunately for the protagonists, their desires are benevolent. They send both Ushio and Tora back in time to witness the genesis of the mysterious and powerful Beast Spear, in order to provide valuable insight into accessing its power, as well as insight into Ushio’s heritage, and the ultimate course of action necessary for Ushio to fulfill his destiny.

Omamori-Sama is a particular type of yokai known as Zashiki Warashi. It takes the form of a young girl with a boyish haircut, and usually inhabits a house, to which it brings great fortune (although it does occasionally play harmless pranks on the inhabitants). On the show, Omamori is technically a prisoner to the Takatori family, she has formed a kinship with the women in the family line, including the young woman Saya, as they have the unique ability to see spirits.

She foretold of a prophecy wherein Ushio, using the power of the Beast Spear, would free her from her imprisonment. But even after the prophecy is fulfilled, she continues to watch over Saya and her household, while helping Ushio and Tora on their quest.

Perhaps one of the fearest foes faced by the series’ protagonists, Guren’s history is a viciously bloody one. Centuries ago he was a human who went by the name of Sokuei, a mercenary with a mean streak who used the Beast Spear to slay yokai and human alike. Such was his lust for blood that his soul was warped by the Beast Spear, and he transformed into an azafuse, the same tiger-like demon as Tora. However, unlike most azafuse, his coloration is pitch black, to match the evil and cruelty inside. When he embraced his inner demons, he cast off his human name, and became Guren.

While he has the powers inherent in all azafuse, his true power comes from his utter ruthlessness, as he is willing to commit acts of unspeakable atrocities. He also has the secret ability to create lookalikes, which essentially makes him the leader of his own one-man (or in his case, demon) army. Ushio and Tora are forced to enlist the help of the Chinese exorcist, Hyou, to have any hope of overcoming him.