The main characters of the series are the "Family" (家族, Kazoku), a group of kids led by Seiko dealing with the supernatural.
After being possessed by the Turbo Granny, Okarun gains the ability to enter a powerful demonic state, granting him immense speed but also a suave yet lethargic alternate personality.
Although she puts on the appearance of a ditzy and amiable person, she is actually incredibly vain and boasts a Messiah complex, a direct result of her inability to reconcile with the death of her mother at a young age.
The resulting confrontation culminated in her absorbing Acrobatic Silky's powers, giving her a similar transformation to Okarun as well as immense agility and prehensile hair.
Though considered an attractive and athletic jock, Jiji is actually an eccentric dork who constantly throws praise onto others and views everyone in a positive light.
Despite his overall social ineptitude, he has invaluable imagination skills that work well in tandem with nanoskin, an alien technology that allows anything the holder visualises to become reality.
After dealing with the lasting grudge of a deceased childhood friend, she obtains yōkai-fuelled gravity powers based upon her ability to sing.
Manjiro (万次郎, Manjirō) is Seiko's pupil and a spirit medium who is asked to help out in the Evil Eye case.
The Hayashi (囃子) are a band of musicians who sometimes help Seiko exorcise evil spirits using Heavy Metal music.
After being led to obtain one of Okarun's testicles, Unji makes an attempt at beating a supernatural diorama board game named Danmanra.
His species (whose speech consists largely of gargled, unpronounceable characters) has immense endurance, can shift into a more powerful form, and like an actual mantis shrimp, attacks with bullet-speed punches.
Peeny-Weeny reluctantly takes these missions as his son, Chiquitita, has a terminal illness that causes him to lose blood constantly, requiring daily transfusions, and which also killed his wife.
Evil Eye (邪視, Jashi) is a powerful and sinister yōkai born as a human sacrifice in the feudal period.
The Evil Eye, in addition to its immense physical abilities, uses the grudges of the sacrificial victims to form powerful, nigh-invincible constructs which frequently manifest into something akin to a soccer ball.
Adachi (足立) is the teacher of class 2E at Kami High, who is manipulated to attack powered people with her Jiangshi Chinese zombie summonings.
Acrobatic Silky (アクロバティックさらさら, Akurobatikku Sarasara) is a powerful yōkai who possesses immense size and enhanced strength and flexibility.
In her human life, she was a single mother and an aspiring ballet dancer, but was forced into odd jobs, including as a prostitute, to make ends meet and support her daughter.
Her life ended up falling apart when her pimps kidnapped her daughter and brutally assaulted her in order to collect payment, leading her to commit suicide.
Fairy-Tale Card (メルへンカルタ, Meruen Karuta) is a yōkai sealed within the Danmanra board game and the creator of the cursed trunk's inner world.
Count Saint-Germain (サンジェルマン伯爵, Sanjeruman Hakushaku) is an alien and an affiliate of the Kur, working as the deputy head teacher and advisor of the History and Culture Research Club in Momo and Okarun's high school, while under the assumed name Sanjome (三丈目).
Pygmies (小人, Kobito) are diminutive people that wear conical hats and masks and are able to stitch and weave at incredible rates.