This is a list of characters that have appeared or are mentioned in passing in the Story of Evil junior novel series.
Elluka was an expert on demons and an acquaintance of Haruto, with "Elluka" being her screen name on an SNS chatroom. Haruto at one point contacted her using the screen name "Leon," explaining that he had a friend possessed by a demon and needed help. "Elluka" was able to identify the demon in question as being a "paper demon," and she claimed that she could provide an exorcism for a fee.
Masaki later confronted Itsuki about entering the archive and explained the nature of the demons to him, introducing him to Rahab and Gilles. Itsuki learned, among other things, that to break his contract with Marie he needed to write a story that would be accepted by the demons. When one of the demons, Salem, was discovered missing, Itsuki enlisted Shigumi and his cousin Haruto to go find him, without telling Haruto the truth of the demons. They eventually discover the demon was stolen by the broke lawyer Maguchi.
After Salem was stolen from Maguchi in turn by a college student on a bike, Itsuki and his friends pursued him until Itsuki eventually confronted the student on the roof of a building. Just as Itsuki had recovered Salem, a gust of wind blew the demon out of his grasp and he fell over the side of the roof to catch it. He was rescued by Marie, and afterwards wrote a ten page story about his adventures while talking things over with Haruto and Shigumi.
A week after the adventure, he presented his story to all the demons of the archive, with his uncle, Maguchi, and his friends in attendance. After his story was accepted by most of the demons and Tomozou, Itsuki's contract was broken and he encouraged Maguchi to write a story next.
When the demon of greed Salem was discovered stolen, Shigumi was one of the friends Itsuki enlisted to go look for the thief. They eventually found that it was the lawyer Maguchi; when Maguchi was accosted by a biker and Salem was stolen again, Shigumi stopped the biker before they could escape from Itsuki. She later called the police after Itsuki recovered Salem from the biker.
Shigumi dropped by to see Itsuki later and they discussed the story he was writing to break his contract; although she attended a different school, she promised to stay in touch with her new friend. Shigumi was later present when Itsuki broke his contract by presenting his story to the demons of the archive, having Tomozou accept the story when Rahab refused to.
Hosoyoma is an old woman living in Masaki's apartment complex. When the demon Salem was discovered stolen Itsuki and his friends investigated the other tenants, including Hosoyama, but she ultimately wasn't behind the theft.
Afterwards Marie accompanied Itsuki on the search to find the stolen demon Salem; when a college student made off with Salem on a bike, Marie gave Itsuki wings to fly after him before reaching her limit in flight. When Itsuki later confronted the thief on a roof, he recovered Salem but fell over the edge by accident; using her powers, Marie assured he survived the fall without a scratch. When Itsuki wrote up his story to break his contract with Marie, Marie reluctantly accepted the story along with most of the other demons.
Maguchi was a young lawyer living on the fourth floor of Masaki's apartment complex. Deeply in debt, Maguchi broke into Masaki's archive looking for something valuable to sell. Coming upon what appeared to be a 10000 Yen bill, but which was actually the paper demon of Greed named Salem, Maguchi stole it and spent it, unwittingly making a contract with the demon. Later, Itsuki and his friends made an investigation into the theft and Maguchi was discovered.
Confronted by Masaki, Maguchi broke down and confessed his deed; he was later shocked when Itsuki showed to him how the 10000 Yen bill had returned to his wallet, explaining his contract. Maguchi decided to keep Salem anyway and attempted to leave with him, only for a college student on a bike to crash into him and steal the bag. As a result, he was sent to the hospital for a week.
After getting out, Maguchi stood by with all the demons and Itsuki's friends in Masaki's archive and he watched as Itsuki broke his contract using a story about their adventures. Itsuki encouraged Masaki to write his own story to break his contract next.
After Maguchi learned the truth about Salem, he attempted to flee with him, only for a college student to steal the demon instead. Salem was soon after recovered and returned to the archive by Itsuki; he was later one of the demons who accepted the story Itsuki wrote to break his contract.
Haruto later joined Itsuki in trying to track down the person who'd stolen Salem; after Maguchi was discovered as the thief, and was accosted by another thief on a bike, Haruto called an ambulance for him. Some time after Salem was recovered, he dropped by to chat with Itsuki and revealed his knowledge of the demons, as well as how he'd been trying to help with the contract secretly. About a week later, he was one of the ones who stood by and watched as Itsuki broke the contract using a story of their adventures.
When he later discovered Salem was stolen from the archive, Masaki enlisted the help of Itsuki and his friends to find the culprit, who turned out to be a college student also living in the complex. After recovering Salem, Masaki helped break Itsuki's contract by getting out all the demons to accept the boy's story offering.
Unknown College Student
An unknown and broke college student that resides in Masaki's apartment complex. When the demon Salem was discovered stolen, Itsuki and his friends investigated the other tenants, including the college student. Later, the college student crashed into Maguchi, the actual thief, and stole the bag containing Salem. The student's bike was stopped by Shigumi and he fled into a nearby building. Itsuki confronted the student on the roof and, after discovering his identity, recovered Salem from him. The college student was arrested not long after.