Apart from its already large normal cast, there are a number of supporting characters in The World God Only Knows, most of them being family, friends, teachers or other students.
- The World God Only Knows: Protagonists
- The World God Only Knows: Capture Targets
- The World God Only Knows: Gods and Devils
The Katsuragi Family
Keima's mother, an ordinary Japanese housewife... who used to run with biker gangs. She runs a little cafe from the Katsuragi home, "Cafe Grandpa". She loves Keima, but worries about his future. She adores Elsie, whom she thinks is her husband's illegitimate daughter, and treats her like her own.
- Badass Biker/Biker Babe: Used to be one, and hasn't lost her touch, much to Keima's distress◊.
- Beware the Nice Ones: Don't get on her bad side. Ever.
- Boobs of Steel: Just like Mars and the Kasuga sisters, she's quite strong.
- Death Glare: She sported an impressive one◊ when she called her husband after Elsea's introduction to the household.
- Drives Like Crazy: At least, on a motorcycle.
- Expository Hairstyle Change: Whenever she gets angry, she lets her hair down.
- Former Teen Rebel: She was once part of a biker gang
- The Glasses Come Off: A sign someone's about to enter a world of pain.
- Good Parents: To both her son and Elsea who she believes is her husband's illegitimate daughter. There's this one scene in Kanon's conquest arc where she scolds Elsea for staying out late and then hugs her and says how worried she was about her. Then she scolds Keima for not looking after "his little sister".
- Hot-Blooded: Some things she really gets into.
- Long Hair Is Feminine: An odd case of Playing with a Trope. When she's in her pleasant mode, her hair is up in a bun and only reaches its full length when she goes into Iron Lady biker mode.
- Meganekko: Justified; her sight started deteriorating 10 years ago, so she began buying glasses. Keima's inherited the condition.
- Ms. Fanservice: The manga doesn't have much fanservice, but what little there is comes almost exclusively from her. Enough that her end card portrait◊ in season 1 episode 8 is done by Sano Toshihide, an Eroge artist.
- Obnoxious In-Laws: A mild case with her husband's father but she seems to get along with her mother-in-law. Her cafe, "Cafe Grandpa", is named in honor of Denma.
- Otaku: Although it doesn't come up much, Keima does mention that she's a bit of a manga fanatic. Which might be where he got his game obsession, come to think of it.
- Parental Substitute: Elsie is more than willing to call her 'Mom'.
- Rapunzel Hair: When she lets it at the loose, it reaches her waist.
- Red Baron: Used to be known as the "Snow Woman of the Mountain Pass".
- Retired Badass: And still willing to bring the smack-down, as one unlucky groper discovered.
- Woman Scorned: She is not happy when she thinks her husband is cheating on her, while Elsie (and later Haqua as a joke to her upon their first meeting) is actually just making it up.
- Wrench Wench: Shown to have been working on her motorcycle in the first season's 8th episode.
- Yamato Nadeshiko: Her baseline is a kind and loving Japanese housewife but don't forget that "Nadeshiko" is the name of a wild flower.
Keima's father, a man who is almost never home due to travel for work.
- Alliterative Name: His given name and surname begin with the same kanji.
- The Ghost: The closest time when we first get to see him is in Keima's flashback but his face is blocked.
- Mistaken for Cheating: Elise (and Haqua as a joke) claim that Keiichi is their father. When Mari angrily calls him about having slept with other women, he's understandably confused about it.
- When You Coming Home, Dad?: He is often overseas for work.
Keima's grandfather and Keiichi's father. He once lived in Maijima City but gave his house to Keima's family when their house was destroyed in an earthquake 10 years prior to the story. He and his wife now live in Yamaguchi Village.
- Doting Grandparent: He loves his grandson Keima. He keeps the stuff that he sent to him and even worked hard and made a bowl and decorated it with a game character for him.
- Obnoxious In-Laws: A mild case with Mari.
- Terrible Artist: His attempt at a picture of one of Keima's dating sim heroines is really bad.
Maijima Private Middle/High School Characters
Keima's homeroom teacher and the senpai of Jun Nagase. She frequently abuses Keima, but (like the rest of his teachers) has mostly given up on scolding him.
- Action Girl: Her fight against Lune shows us what she's made of.
- Aloof Ally: She's captured two escaped level four spirits single-handedly but since she's working on a different mission, hasn't revealed herself to Keima's group. What her job is and what her intentions are remain unknown, though it's clear that she opposes Vintage and other similar groups. Eventually it is revealed WHY she's aloof. She and Keima, in the past, agreed to act like they don't know each other should they ever meet again... but she also promised to always be by Keima's side to protect her onii-chan.
- Alternate Self: It is revealed that she is this to Dokurou Skull.
- Animal-Eared Headband: She wore a headband with cat ears in the outfit she wore for the teachers' skit.
- Anti-Hero: She's definitely one of the good guys, yet she's quite brutal against her opponents and doesn't hesitate to kill them.
- Badass Bystander: Gets called out to capture Level Four Weiss, but is working on a different mission from the rest of the Runaway Spirit Squad. For over ten years, with the help and inspiration of a time-traveled Keima, she sets out to enact the chain of events that lead to Keima foiling Vintage so that all the fighting can end.
- Badass Teacher: She's Keima's teacher and later chapters show she's quite the Action Girl.
- Bare Your Midriff: Had this gig on for her later appearances during the Heart of Jupiter arc, as evident in the cover of Volume 25.◊
- Brought Down to Badass: She is Dokurou, the super-powerful devil who helped Keima in the past, but in the present mentions that she's basically just human now. She still has access to some pretty powerful magic, though, just not the "curb-stomp everything the enemy sends at us" kind.
- Chekhov's Gunman: Appears very early, but doesn't really do anything until Yui's arc.
- Clingy Jealous Girl: She kept on taking PFPs from Keima and beating him for playing dating sims in class because she was jealous that her "onii-chan" was paying attention to other girls, in games and later out of games too, and not to her.
- Collared by Fashion: Wears a studded collar. Given the nature of the collar, the studs are likely glued on.
- Dark Is Not Evil: Has dark hair and mostly sports dark-colored clothing, but is a stern yet decent teacher who also works from the sidelines in capturing Weiss.
- Fanservice Costumes: The outfit◊ she wore for the teachers' skit was a half jacket to leave her front and waist exposed and dominatrix boots.
- Good Is Not Nice: Turns out she knows a lot more about New Hell and Keima than she lets on... but she'll still beat the crap out of him and makes an effort not to let him know about her own involvement.
- Green-Eyed Monster: It turns out this was one of the reasons she was so hard on Keima.
- Hidden Heart of Gold: She acts stern and aloof and can be quite violent towards Keima. However, later chapters show she's actually a very nice person who cares about others. Her aloofness is actually an act she has to put on since she and Keima agreed to act like they don't know each other should they ever meet again.
- Hot Teacher: During Nagase's omakes, she disapproves of how Nikaido's style 'tempts' students before having a brief memory flash of kissing Keima.
- Not So Stoic: Nikaido is normally quite cool and collected, even when dealing with rude or hostile people. However, the moment that Keima not coming back becomes a very real possibility, her composure is shot and she is reduced to crying out to Keimanote in the hopes that he is not forever lost to time, showing that despite everything, Dokurou/Nikaido never loved Keima any less than ten years ago.
- Sadist Teacher: To an extent, with some Stern Teacher thrown in as well.
- Sempai/Kohai: To Jun.
- She Is All Grown Up: Comparing her past self from the flashback arc to her present self.
- Sugar-and-Ice Personality: Normally cool and collected, but she does show a softer side later in the series after she reveals her identity as Dokurou and her remaining love for her "onii-chan" Keima.
- Whip It Good: In her costume for the teacher's skit.
- Zettai Ryouiki: Sports a Grade-C in her latter appearances during the Heart of Jupiter arc.
A classmate of Keima who is a member of the track-and-field club with Ayumi then later in Chihiro's band, the 2-B Pencils.
- Boring Yet Practical: She goes and studies in a cram school unlike the other members of 2-B Pencils.
- Spanner in the Works: For Keima when he is trying to talk to Ayumi during the Old Conquest Arc by bringing up the rumors of him with Kanon.
- Unwitting Muggle Friend: One of Elsie's friends in Maijima, she doesn't know about Elsie being a demon or the other supernatural happenings.
- Wrestler in All of Us: She casually pins down Keima (with the Walls of Jericho at that) midway into Ayumi's reconquest.
- Youthful Freckles: From running in track-and-field, they disappear sometimes.
Keima's classmate who appears from time to time.
- Art Evolution: She looks a bit different when comparing her from her initial manga appearance to her current appearance.
- Class Representative: She's the class representative and can occasionally be seen giving out handouts and such. However, despite her decently important position in the class, the author never got around to giving her a name.
- Girlish Pigtails: Her original look has them hang behind her while her current look has them in front.
- Meaningful Name: Mobuko means "mob-girl" referring to her status as a mob character.
- Recurring Extra: She appears often when scenes are in or involving class 2-B.
An English teacher in Majima Academy, and the homeroom teacher to class 3-D.
- Evil Is Petty: Well, he's not really evil per se, but.... During one of his test, he promised that he only approves extracurricular activities if the students get perfect grades on his test. Then, after the test, he happily approves everyone's activities despite their score. Why? Because Keima, who he hates because he keeps playing games during lessons but always gets perfect scores, scores 99 out of 100.
- Gratuitous English: Despite being an English teacher and thus having an excuse to use the language, he doesn't appear to be that good at it.
- Big "NO!": Bellows out an "Oh, No!" in the first episode of the Goddesses Arc, upon seeing Kanon cling onto Keima.
- Sadist Teacher: He really picks on Keima. And like most of Keima's teachers, gets pawned come the major exams. Save for that one instance. See above.
Head of the library committee.
- Girlish Pigtails: She has long pigtails, braided to make her look more serious.
- Nerd Glasses: Fujidera has a rather fussy, businesslike attitude, which is complemented by her glasses.
- Reasonable Authority Figure: When Shiori takes over the library, she goes out of her way to avoid telling the teachers despite it being the easiest solution since she doesn't want to get Shiori in trouble. After she manages to get in, she agrees to a compromise with Shiori to save as many books as possible.
A group of delinquent students.
- Butt-Monkey: They usually get beaten up or scared off by strong females whenever they appear.
- Delinquents: They loiter, litter, be mean, and get into fights.
- No Name Given: At the time of their introduction only one of them is named: "Ryou", the tall delinquent.
- His full name, as revealed in the official guide book, is Ryounuske Nakamura.
- Production Throwback: They first appeared in an earlier work called Seikesshou Albatross as 3rd year middle-school delinquents harassing the main heroine Asakura.
- Recurring Extras: They appear occasionally from time to time. They usually cause trouble when they do.
Haqua's partner, a middle-aged Gokult saleslady. Not the fastest of workers, especially now she's getting on, but not to be underestimated either.
- Amazingly Embarrassing Parent: She's basically this for Haqua, even though they're not actually related and Haqua is easily 200 years older than the human. Particularly her habit of pushing Gokult merchandise on any likely takers.
- Boring Yet Practical: Her spirit-capturing method is to simply talk to the host every day. While slow, she's working on so many at once that Haqua's record is actually quite good.
- Fun T-Shirt: Wears one that says, "NO PUNK NO LIFE".
- The Load: Subverted. She's not useless, she works slowly, steadily and patiently on her targets. Haqua, being rather less patient and feeling the need to prove herself, initially dismisses her, with unfortunate results.
- Shipper on Deck: Although not outright stated, she seems to try to manipulate Haqua and Keima getting together. Such as telling Keima that Haqua must be in a good mood because of him and how she supposedly talks about how good-looking he is. She also insists on him taking a bath and then tells Haqua that he already went home when she herself wants to take one. Keima is able to see through it though, unlike Haqua.
Ryou is Nora's partner, and apart from standing around being pretty doesn't seem to actually be good at anything. Due to his incompetence, Nora tends to end up doing most of the work, leading to unpredictable results.
- Big Damn Heroes: Surprisingly enough, he is the one to save Keima when Lune is looking for Fiore's signal and Keima is out with a cold.
- Bishōnen: Pretty, but dumb.
- Brainless Beauty: He is handsome but kinda stupid.
- Brainwashed and Crazy: An omake reveals that Fiore managed to brainwash him into joining Vintage's side and shouting Vintage slogans. Fortunately, Ryou's incompetence and inability to get her out of her jar aside, it was far too late for either of them to affect the outcome and after a good knock to the head Ryou returned to normal.
- Bumbling Sidekick: According to Nora he's useless. He himself says that it ends quicker when he helps, though. Of course, the one time we see them working together he just gets in the way.
- Butt-Monkey: According to the author's notes he's matched only by Elsie.
- Dumb Blonde: He's essentially brainless and can't even left or write or how to write his own name. He is, however, confident in his attractiveness and seems to enjoy flipping his blond hair.
- Handsome Lech: Only working for Hell because he likes Nora's boobs.
- Running Gag: Ryou is terrible at kanji and can't even write his own name. He always writes "Bald" on accident.
- Something About a Rose: The majority of his appearances has him holding a rose. The rose also holds his notes.
An idol group that was composed of Lime, Yuri, and Kanon. They broke up sometime before Kanon began her solo career.
- Blonde, Brunette, Redhead: Lime, Yuri, and Kanon respectively.
- Breakup Breakout: After the group broke up, only Kanon is seen to continue on the idol path.
- Face of the Band: In-universe according to an omake, Lime was the original face until Kanon took off her glasses.
- Girl Group: They were this before breaking up.
- Mega Twintails: Lime's hair style.
Reiko Hinaga's granddaughter.
- Creepy Child: She says and does creepy things like chanting "I'll cut off your head". Her grandmother says that is why she has no friends because she scares people.
- Creepy Doll: Has one made of straw.
- Identical Grandchild: Looks like her grandmother when she was her age.
- Precocious Crush: On Keima after the capture arc. She sends him a love letter that actually ends up with Dokurou in hell somehow before getting redirected back to him.
- Red Herring: The ghost in the graveyard looking like her and her apparent socialization issues. However, as stated, Airi isn't concerned with that kind of stuff and wouldn't get a Runaway Spirit.
The Aoyama Household
The Aoyama's chauffeur.
- The Driver: Is this to the Aoyama family even after they lost their fortune. He feels obligated to his deceased boss, Yuuri Aoyama.
- Parental Substitute: Tries to be this for her, teaching her how to be a commoner. Ironically in the past (as shown in the "Heart of Jupiter" arc), he wasn't really mindful of her and once said he had "no intention of looking after a child [Mio]..."
- Plot-Mandated Friendship Failure/Screw This, I'm Outta Here!: After Mio used up her 4 months worth of allowance buying omelette-soba bread, he leaves to be a taxi driver. The omake shows that he returns to her side after her conquest.
Mio's father, a president of a company before his death.
- Death by Origin Story: His death is one factor causing his daughter Mio to develop a gap in her heart.
- Disappeared Dad: He's Mio's father and he died one year before the series started.
- Posthumous Character: He died one year before the beginning of the story. We see him alive 10 years ago during the "Heart of Jupiter" arc meeting with Shoutaro Shiratori.
The Goido Household
The matriarch of the Goido household.
- Dynamic Entry: She first appears running and pushing Keima away from Yui since she thought that Keima had "attacked" Yui.
- Education Mama: Having Yui quit her club in order to focus on her studies seems to have been the last straw for a gap to develop.
- Kimono Is Traditional: She appears to be quite traditional and wears traditional clothing.
- My Beloved Smother: She goes more than a little overboard fussing over Yui and tends to be very controlling of her, though she doesn't realize it. She pushes Yui into a stressful life she can't complain about and simply considers Yui a good daughter.
- Unnamed Parent: She's always referred to as mother by or Yui's mother because that's all her role in the story is.
The Shiratori Household
One of the Shiratori's stewards, she watches over Urara.
- The Driver: She drives Urara around and socializes with Yui and Mio's drivers.
- Girl Friday: Other than taking care of Urara, the president also has her look over the construction site.
- Maid and Maiden: Her relation with Urara.
- Parental Substitute: Her peers, Morita and Okamoto, joked on her acting motherly that she should become Urara's mother for real.
Urara's grandfather and the president of the Shiratori company.
- Cool Old Guy: Though old, he looks young and handsome. He also knows a little bit about devils and is trying to construct some defenses. Keima tells him to cool it, though, and just play with his granddaughter.
- Dirty Old Man: Considering the porn magazines he keeps in his room...
- Half the Man He Used to Be: In Keima's 3rd attempt, he tried to fight a devil and ended up like this. Good thing there was a reset.
- Just in Time: In FLAG 252, he busts through the library to save Keima, the Goddesses Mercurius, Vulcanus and Minerva, and their hosts Ayumi, Tsukiyo and Shiori.
- Married to the Job: While he would always be there for his family when they really needed it, he otherwise didn't spare them a thought. A runaway spirit posing as his daughter-in-law helps him realize his shortcomings and promise to take better care of Urara.
- Older Than He Looks: He's a grandfather, but looks like a handsome young man. Even after 10 years later, he still looks the same.
- Revenge: His motivation to fight the devils.
- You Are Not Alone: Urara saw how lonely he was after her mother and father's deaths. The gap in her heart came from her inability to fill his loneliness.
Urara's mother and Shoutarou's daughter-in-law who was possessed by a devil.
- Demonic Possession: She get possessed by a Runaway spirit when Urara was about 3, which caused her to lash out against the servants and her husband.
- Final Speech: When the devil posing as Kayoko is defeated, it apologizes on Kayoko's behalf for being so selfish, wishing that she could have played with Urara longer, and asks Urara to stay strong.
- Gilded Cage: How she saw the Shiratori Household.
- Go Mad from the Isolation: Urara's mother was very happy at first to marry into the Shiratori family, but her husband and father in law were almost never home. The servants around the house respected her as the lady of the house and avoided bothering her. Though she became increasingly lonely, she also felt reluctant to disturb the "perfect world" surrounding her. Eventually, her despair drew an extremely powerful runaway spirit into her heart, driving her mad. Using Powers via Possession, she ended up murdering her husband and many of the servants before dying herself.
- Knife Nut: Her apparition wielded a knife and it is implied that she herself also used one to massacre the servants and her husband.
- Missing Mom: Is this to Urara.
- Posthumous Character: She died when Urara was about 3.
- Powers via Possession: Using the powers of the devil she was possessed by, she murdered the servants and her husband out of rage that none of them interacted with her.
- Shapeshifter Guilt Trip: The devil that possessed her takes her form long after her death in order to play with Urara and guilt trip Urara's grandfather into backing off.
Maijima East Elementary School (10 years ago)
A three girl group made of 4th graders armed with water guns. They consist of Mami, Emi, and Yumi.
- Blonde, Brunette, Redhead: Mami, Yumi, and Emi respectively.
- Jobbers: Keima described them as such. No soon after they appeared Kaori came, showed them up by being prim and proper, and their ranks go down. They later get rundown by the Maijima Alliance.
- Shout-Out Theme Naming: The girls are named for three Magical Girl series by Studio Pierrot.
- Water Guns and Balloons: Their weapons of choice is the former.
A muscular elementary schooler.
A comedy duo made of Maiko and Mariko.
- Boke and Tsukkomi Routine: Their comedy act with Maiko and Mariko as the respective "boke" and "tsukkomi".
- Facial Markings: Both have a star-mark on their cheeks; Maiko's on her right while Mariko's on her left.
- Meganekko: Mariko, with her large lens glasses.
- Multicolored Hair: Maiko has two hair colors.