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Mystery Research Club
In General
The Mystery Research Club is introduced as a club on the verge of being disbanded due to only having 3 members and the school requiring a minimum of 4 members. Daisuke stumbles into the clubroom at the best possible time and forcibly recruited, though he eventually starts going to the club on his own volition.
The club was actually formed by Kotone Oohara, Chiaki Kanda and Suzu Ninomiya because they were unable to set up clubs of their own (Hypnotism, Magic and Occult respectively), forcing them to create a more general "Mystery Research" club instead. Nonoka later joins following the disbanding of the Science Club.
- Boke and Tsukkomi Routine: While generally Daisuke plays the role of the Tsukkomi, the interactions between the club members often have this vibe and who plays what role can differ depending on the situation.
- Oh, Crap!: Each of the Mystery Research Club members barring Daisuke and Kotone can inspire this reaction in other students and the faculty.
- Ragtag Band of Misfits: How the club is viewed by other students and faculty.
- True Companions: The members of the club become very close to each other as time goes on, and they generally have each others' backs. It's rare for them to bicker among themselves and the members usually go along with whatever plan or idea any of the others happen to have.
- The Unfettered: Part of the reason Daisuke stays with the girls is because he realises if he's not around, then the girls will then start wandering around looking for other victims instead. Reiko Takahama of the Public Morals Committee is forced to concede his point.
Daisuke Goryou
Daisuke Goryou
School Year: First
Interest: N/A
First Appearance: Chapter 1 ("Welcome to the Mystery Research Club")
A first year high school student at Nanshou High School, Daisuke finds himself roped into the Mystery Research Club when he mistakes their club room for the school storage shed.
- Attractive Bent-Gender: Much to his chagrin. Both Kokkuri-san (in Asahi's body) and Kotone note that he's cute as a girl before recognizing him (although Kotone doesn't say it out loud), and he's scouted by the Drama Club for the lead role of their Snow White play due to having a "talent" for cross-dressing.
- Clueless Chick-Magnet: As time goes on, it becomes pretty clear that Daisuke has become this. He's been described as being fairly ordinary-looking, but Yoshizawa Kaname of the Newspaper Club mentions that he's kind of cute. That said, the various girls who have a thing for him are generally attracted by his Nice Guy tendencies.
- Conditioned to Accept Horror: Being in the same club as Chiaki, Suzu and Kotone has given him an incredible amount of patience and the ability to just shrug off things that would shock most people. When the president of the Kotone Oohara fan club is left shaking in terror after participating in one of Chiaki's magic acts, Daisuke laughs when he recalls he barely survived when Chiaki tried the same trick on him.
- Desperately Looking for a Purpose in Life: Downplayed; he still hasn't officially declared a subject of research, although he does pretend to have an interest in UMAs during Chapter 105 to get the other club members off his case.
- Digging Yourself Deeper: Sometimes his attempts to avoid trouble winds up making things worse for him, such as the time he tried to get Yui to explain to their mother what kind of relationship he has with Suzu, only for Yui to tell their mother he and Suzu are so close they even sleep together.
- Another example crops up in Chapter 199 ("The Mystery of Violating School Regulations"), when he tries to turn the tables on Public Morals Committee chairman Nadeshiko Yawata by pointing out her uniform is against regulations while she's scolding him about all the times he's caused chaos around school. Nadeshiko immediately starts stripping to remove the offending item, just as Reiko walks in and is told, "he told me I had to remove my clothes..."
- Disguised in Drag: He cross-dresses multiple times in the series out of necessity, with an increasing worry that he's becoming used to it.
- Here We Go Again!: Sometimes has this reaction when he recognises the similarities between any shenanigans going on and previous occasions.
- Heroic Sacrifice: How he convinces Reiko Takahama to stop trying to get him to quit the Mystery Research Club. He points out that if withdraws, the club is disbanded. If the club is disbanded, instead of Chiaki, Suzu and Kotone being gathered in one place comparatively far from the main school campus, they would now be free to wander the halls and there'd be nothing anyone could do to stop them. Therefore, him remaining in the club as a guinea pig gives them a safe outlet for their various quirks.
- I Didn't Mean to Turn You On: One of the major reasons so many girls are attracted to him (or become attracted to him after getting to know him) is thanks to his tendency to say sweet or reassuring things to them and be completely earnest about it. For a few examples:
- When accompanying Suzu and Yui for swimsuit shopping, he assured Suzu she'd look cute in any swimsuit she chose because she's the one wearing the swimsuit.
- When he first meets Chiaki's younger siblings, he genuinely praises her for being such a doting and responsible big sister.
- When Kotone loses confidence in her hypnotism, sending her down a spiral of low self-esteem, he does everything he can to help boost her confidence.
- When Nonoka was depressed about the disbanding of the Science Club and mentions she doesn't care much for people and prefers watching how chemicals react to each other, he points out that people coming together and working as one is comparable to a chemical reaction. This is what prompts her to join the Mystery Research Club despite waffling about it earlier.
- Not What It Looks Like: Sometimes winds up in these situations, like the time he encountered Asahi-sensei when she was caught in the rain nearby his house and offered the use of their shower so she wouldn't catch cold... only for his mother to run into Asahi-sensei just after she finished showering and coming to the conclusion Daisuke sneaked a girl into the house while she was out.
- Oblivious to Love: While he's definitely attracted to many of the girls he's close to, he seems completely blind to their genuine affection for him. A few examples:
- He gets plenty of Ship Tease with Reiko, but while on some level she accepts she likes him on his part he treats her with a certain amount of distance (shown when she addresses him as "Daisuke-kun" but he addresses her as "Takahama-san"). At least part of that can be chalked up to the fact that she's his senpai in addition to being a member of the Morals Committee.
- Suzu's feelings for him are pretty blatant, but he seems completely blind to them. At least part of this can be chalked up to Suzu's own personality.
- Something Else Also Rises: Daisuke is a healthy teenage boy, and so when the stimulation gets too much he often winds up crouching, slouching or otherwise desperately trying to divert attention so the girls don't notice he's now sporting an erection.
- In one early example, when the Mystery Research Club was playing Musical Chairs Suzu took a third option by sitting on the seated Daisuke's lap. A combination of her scent and sensation of her sitting on him was enough stimulation for him to hurriedly admit defeat and stand up before she felt a certain something poking her.
- Teacher/Student Romance: Asahi-sensei is a young attractive teacher, so there are times where he has Something Else Also Rises reactions when she accidentally presses her sizable bosom against him.
Suzu Ninomiya
Suzu Ninomiya
School Year: First
Interest: The Occult
First Appearance: Chapter 1 ("Welcome to the Mystery Research Club")
A first-year student, although not in the same class as Daisuke. Suzu is infamous for her love of the occult, as well as her cursed doll Matsuko.
- A-Cup Angst: She's well aware she's not exactly a buxom babe, and is generally pretty accepting of it. That said, she also isn't very happy when, say, she has to wear an outfit that draws attention to how flat she is.
- Angry Cheek Puff: Suzu is a high schooler who looks so young and small that people mistake her for a middle schooler. This greatly displeases her and makes her liable to pout by puffing her cheeks, which ironically makes her look even more like a kid.
- Berserk Button: Very understated, but reminding her of how short she is or how young she looks (thanks to her height and build, she looks closer to a middle schooler like Yui than a high schooler) is liable to make her pout or puff her cheeks.
- Mocking or not believing in the supernatural is played a bit more straight, though she never goes as far as to yell.
- Blank Stare: Often gives one in reaction to the frequent insanity going on around her; even her normal expression has shades of this.
- Companion Cube: She carries Matsuko pretty much everywhere she goes, though she at least leaves Matsuko behind when, say, going shopping or hanging out with Daisuke's sister Yui.
- Crush Blush: Occasionally has one when Daisuke gets to her.
- Dope Slap: In Chapter 186 ("The Mystery of Radio Calisthenics"), Suzu observes that Kenta (Chiaki's younger brother) probably likes Yui. Daisuke laughs off the suggestion, claiming that he'd surely notice if someone's feelings were so obvious. In response, Suzu (ostensibly doing the calisthenics) swings her arms right into his stomach while pouting furiously.
- The Dreaded: Suzu has a negative reputation throughout the school due to Matsuko and her obsession with the occult, with most people afraid to approach her in fear of being cursed. She occasionally weaponizes this, most notably during the first club competition and the cavalry battle during the second athletic festival.
- I Just Want to Have Friends: While she generally gives off a stoic, deadpan air, her internal monologue suggests that while she accepts her interest in the occult scares people away she really would like to have friends. It's part of the reason she adores Yui so much, since Yui not only isn't scared of the occult, she accepts it as part of Suzu's personality without hesitation.
- She also is pleasantly surprised when the trio of classmates she is forced to join in Chapter 94 ("The Mystery of Cavalry Battles") make an effort to befriend her in Chapter 118 ("The Mystery of Trash Collecting"). She's even more happy when they approach her in class in Chapter 174 ("The Mystery of Friendship") and take off their various warding charms to signify they want to be her friend without being frightened of her reputation... or Matsuko.
- Kuudere: Despite being pretty deadpan most of the time, she's also the one who's most comfortable hugging or touching Daisuke. Of the girls interested in Daisuke, she's easily the most aggressive.
- She's much friendlier and cheerful with Yui.
- Nightmare Fetishist: If it has anything to do with the supernatural, especially ghosts and curses, Suzu is into it.
- Redheads Are Uncool: Has wine-red hair, and isn't very popular at Nanshou High School due to her occult obsession.
- Signature Headgear: She always wears a pink ribbon in her hair. In fact, when she asks Daisuke for his opinion on what colour swimsuit she should get, he suggests pink because he figures since she always wears her pink ribbon pink is her favourite colour. He's right, and she's touched he notices.
- Sitcom Arch-Nemesis: Is this with Nonoka, who refuses to believe in the supernatural.
- Gets worse when she notices Nonoka and Daisuke actually get along really well, making her jealous.
- Sleep Cute: Engages in this with Daisuke in Chapter 198 ("The Mystery of Sketching Sessions").
- The Stoic: Downplayed. She's not completely stone-faced, but she tends to emote less than the other club members (barring the first few chapters).
- Third-Option Love Interest: In a played for laughs example, when Reiko and Chiaki are arguing about who should share an umbrella with Daisuke she slips in and gets to walk with him instead (much to their outrage).
- Throw the Dog a Bone: After numerous occasions where her Clubmates (and even Nonoka-chan) have had supernatural experiences but she hasn't, Chapter 353 ("The Mystery of Graveyards") finally has her get shoved by something invisible. Why is this significant? She and Daisuke were standing in front of her mother's grave, and it's all but confirmed her ghost shoved Suzu right into Daisuke's arms. Suzu for her part definitely feels it was the case, and is overjoyed by it.
- Troll: Seems to enjoy messing with her club members (especially Daisuke), up to and including faking her death for a Halloween prank.
Chiaki Kanda
Chiaki Kanda
School Year: Second
Interest: Magic (specifically stage magic)
First Appearance: Chapter 1 ("Welcome to the Mystery Research Club")
A second-year student that's well-known at Nanshou High School for her athletic ability.
- A-Cup Angst: Less so than Suzu, but she does still worry about it when physical examinations roll around.
- Berserk Button: Challenging her abilities as a magician.
- The Big Guy: The most athletic of the club members; her physical strength gives her nearly as much of the Dreaded status as Suzu, and she's the only one to not need a gimmick during the club competition.
- Book Dumb: While her grades aren't referred to directly, she actively avoids studying unless hypnotized into doing so.
- Can't Hold Her Liquor: She gets drunk very quickly, to the extent that she gets inebriated once from having booze splashed on her.
- Cool Big Sis: To her three younger siblings. Daisuke notes that their genuine adoration of her magic is likely where her overconfidence springs from, and that they take after her natural curiosity and energy.
- Cute Little Fangs: Often drawn with a single fang when her mouth is open.
- Does Not Know Her Own Strength: She frequently injures Daisuke when clinging to him while scared, and somehow shreds her own clothing along with the ropes when escaping from bondage.
- The Dreaded: While she's more popular than Suzu is, her "superhuman strength" is cited as one of the main reasons Kotone's fans won't approach the Mystery Research Club.
- Dumb Muscle: Downplayed. She's not stupid, but she believes that magic takes "effort" (i.e. bending silverware through brute force, or escaping bondage by forcing the ropes open) and doesn't like researching or studying.
- Girlish Pigtails: Although they're smaller than the norm.
- Lovable Coward: She reacts poorly to horror and supernatural phenomena; Daisuke at least finds it cute, although she's embarrassed by it.
- Security Cling: Hangs onto Daisuke a few times when scared, often injuring him in the process.
- Sick Episode: Comes down with a cold in Chapter 71 ("The Mystery of Sick Visits"); Daisuke visits her by request of the club, which she isn't particularly thrilled about.
- Stage Magician: She tries, at least. Most of her "tricks" involve brute force, or are hazardous to her assistant (usually Daisuke, who nearly gets cut in half once).
- Tsundere: Type B. She's friendly most of the time, but she frequently snaps at people when flustered or when her magical "abilities" are called into question (or when alone around Daisuke).
- Vitriolic Best Buds: Daisuke tends to argue with her more than the others (especially early on, when her ego was in full force), but they become close friends over the course of the series.
Kotone Oohara
Kotone Oohara
School Year: Third
Interest: Hypnosis
First Appearance: Chapter 1 ("Welcome to the Mystery Research Club")
A third-year student who is frequently believed to be a School Idol. Kotone is the president of the Mystery Research Club, and the one who got Daisuke to join (although not by choice).
- Aloof Dark-Haired Girl: Kotone occasionally tries to invoke this, partially due to her position both as the Club President as well as her being the only third year of the Club.
- Beware the Nice Ones: While she's ordinarily a Nice Girl, her hypnosis can be dangerous (Daisuke gets easily tricked into joining the club despite being skeptical of her, and later nearly chokes when she forces him to hold his breath).
- Buxom Beauty Standard: She has a busty figure, which is part of why she's a Dude Magnet in school.
- Character Development: Over the course of the series, she learns to rely less on the "cool" image she built up as a hypnotist, and acts more natural around the rest of the club.
- Dude Magnet: She's considered to be very pretty and is very popular with the boys.
- Forced Sleep: One of her abilities, although unusually for a hypnotist she rarely uses it (her hypnosis instead takes effect almost immediately).
- Hoist by Her Own Petard: Daisuke uses her 5-yen coin to hypnotize her in Chapter 15 (although she reveals that she was acting in order to give him a chance to turn the tables on her), and she later hypnotizes herself in Chapter 27 ("The Mystery of Flower Viewing") after being tricked into thinking the group was actually consuming alcohol, depriving Daisuke of his last chance at breaking the hypnosis before Asahi shows up.
- Hypno Pendulum: Uses a 5-yen coin attached to a string, later "upgrading" to a 50-yen coin in Chapter 96 ("The Mystery of Image Changes").
- Mass Hypnosis: Uses this by accident in Chapter 120 ("The Mystery of Image") after being encouraged by Daisuke, and intentionally in Chapter 171 ("The Mystery of Bands") to fool the audience into believing the Mystery Research Club's performance was legitimate (although she later reveals that she can't actually hypnotize that many people at once, and that they only succeeded because of Suzu's keyboarding abilities).
- Not So Above It All: Discussed in Chapter 59 ("The Mystery of Trust I"); she worries that the Mystery Research Club is beginning to lose trust in her as a senior member, but Daisuke mentions that she's more approachable the way she is now.
- School Idol: She's popular enough to have a fairly large fan club, and later recruits Daisuke as her "manager" in order to protect him from them.
- Signature Headgear: A yen coin attached to a hairclip; the coin doubles as her main means for hypnosis.
- Weight Woe: She starves herself in the first physical examination chapter in order to get her weight as low as possible, and later on insists that the scale is broken when she's measured as 75 kg.
Asahi Kasugano
Asahi Kasugano
School Position: Health Teacher, Mystery Research Club Advisor
Interest: Divination
First Appearance: Chapter 20 ("Mystery of the Advisor")
A health teacher at Nanshou High School, and the Mystery Research Club's faculty advisor.
- Demonic Possession: Falls victim to this twice - first in Chapter 72 ("The Mystery of Possession") after Suzu summons the spirit of Nakayama Hanako, and again in Chapter 126 ("The Mystery of Kokkuri-san") when Chiaki interferes with a round of Kokkuri-san.
- Drives Like Crazy: Downplayed, but she does drive recklessly enough that Daisuke gets thrown into Kotone and Suzu in the back seat when turning.
- Dull Eyes of Unhappiness: Slips into this every now and then, either due to her loneliness being brought up or when she gets sick in Chapter 166.
- Easily Impressed: She's impressed with Chiaki's "magic" and Kotone's hypnosis attempt (even though the latter backfired due to Asahi misunderstanding what she said), leading the others to (silently) label her an airhead.
- Fortune Teller: Takes up divination as her research subject from Chapter 31 onward, although she doesn't seem to have a specific focus.
- The Heart: She's brought in as the faculty advisor, and tries her hardest to support the club (although they end up having to take care of her during her occasional mood swings).
- Little Black Dress: She wears a floor-length one when she takes up divination in Chapter 31, coupled with a veil to help sell the Fortune Teller bit.
- Obfuscating Insanity: Possibly; it's not always clear how much of her antics is her messing with the club, or simply being a Cloudcuckoolander.
- Sailor Fuku: She dons Kotone's uniform in Chapter 72 after being possessed by the spirit of Nakayama Hanako.
- Sensei-chan: While she acts professional within the nurse's office, outside of it she's a bit naive, often plays along with the students, and has little luck with love (barring one stint with a love potion that ended in several students and a teacher chasing after her).
- Serious Business: Her profession. After Takahama calls an anatomy textbook lewd while confronting her over aiding the Mystery Research Club in Chapter 23 ("The Mystery of Good Health"), Asahi responds by giving her an explicit lecture on the importance of sex education, and she refuses to let the club hang out in the nurse's office without reason in Chapter 113 due to having a sick patient at the time.
- Sick Episode: Sick Episode: Comes down with a fever in Chapter 166 ("The Mystery of Bad Health"), although the exact illness isn't specified.
- Stepford Smiler: She gets moody when confronted about setting up the Christmas party alone or when the Mystery Research Club does stuff without her, and admits in Chapter 166 that one of her most enjoyable activities is drinking alone while watching television (although she was ill at the time).
- Teacher/Student Romance: Most likely defied, although she does worry about being seen as in a relationship with Daisuke (especially after being caught by his mother in Chapter 141), and gets extremely flustered after both Demonic Possession cases when she ends up in a compromising position with him.
- Womanchild: She occasionally takes her excitability too far, most notably when watching over a kindergarten class with the club in Chapter 176.
Nonoka Hiratsuka
Nonoka Hiratsuka
School Year: First
Interest: Science (specifically chemistry)
First Appearance: Chapter 38 ("Mystery of the Newspaper Club", photo only), Chapter 48 ("Mystery of Science")
A first year and the last member of the Science Club, leading to its dissolution. She is first encountered by the Mystery Research Club when they return after break to discover she'd stumbled upon their clubroom and, thinking it was abandoned, set up shop.
Initially she's invited to come over whenever she wants, but she eventually formally joins the club after prompting from Daisuke.
- Beautiful All Along: Behind her glasses Nonoka is incredibly cute. The first time he sees her without them, Daisuke mentally notes that if the departed members of the Science Club realised the beauty behind her glasses, they likely would never have left.
- In Chapter 225 she's forced to come to school without her glasses after they were damaged in one of her experiments. Many of Kotone's fanboys switch to her newly formed fanclub.
- Because You Were Nice to Me: While Nonoka doesn't seem interested in romance at all, she finds Daisuke's presence reassuring. She is also genuinely grateful to him for coming to her help on the occasions her concoctions get out of hand.
- Blind Without 'Em: Nonoka's glasses aren't for show. Without them everything becomes an indecipherable blob. She actually relies on her sense of smell to identify people when she can't see.
- Boyfriend Bluff: When a couple of pickup artists hit on her at the beach and Daisuke unsuccessfully tries to convince them to leave, she grabs him by the arm and claims he's her boyfriend. It helps that she wasn't wearing her glasses at the time, and her sense of smell identified Daisuke's reassuring scent making her literally grab onto him for comfort.
- Gone Horribly Right: Nonoka is good at what she does. Sometimes a little too good. For example, she once developed a super cleaning fluid to help the Mystery Research Club clean the school pool, but it was so potent it reduced friction to 'zero. Daisuke took one step and wound up rocketing clear across the empty pool and slamming into the wall on the other side.
- Immune to Mind Control: Kotone notes in Chapter 81 ("The Mystery of Trust II") that her hypnosis fails on Nonoka because she doesn't fully trust her (although it may also be because Nonoka is extremely stubborn about not believing in the supernatural); Nonaka eventually plays along to spare her feelings.
- Laser-Guided Karma: When one of the love potion mixtures accidentally spreads throughout the school and causes boys to violently fall in love with her, Daisuke comes to her rescue and tries to get her to safety in the Mystery Research Club's room. Unfortunately, his nose plugs get jarred loose and despite his best efforts he pins her to the ground. Nonoka is terrified, but also accepts what's about to happen as her deserved punishment for getting Daisuke, whose only crime was trying to help her, involved. Luckily Chiaki intervenes.
- Mad Bomber: She attempts to use home-brewed explosives to force open a locked door at school twice, although she's stopped both times before any damage is done.
- It's later mentioned that she's actually known as a Mad Bomber by the student body, which is why the reveal of her very cute face was such shocking news to the general student body.
- Mad Scientist: Yes, to a certain level of "mad". She genuinely loves working with chemicals, but she usually has some sort of objective such as developing a super fertilizer or creating pheromone-based perfume. Unfortunately, her creations are prone to working just a little too well.
- Opaque Lenses: Wears round, spiral-printed glasses. Chapter 225 ("The Mystery of Idols") reveals that they're specially made.
- Sitcom Arch-Nemesis: Is this with Suzu, who is a true believer in the supernatural. Chiaki dismisses such things as unscientific nonsense since they can't be proven.
Other Students
Reiko Takahama
Reiko Takahama
School Year: Second
Club: Public Morals
First Appearance: Chapter 9 ("The Mystery of Public Morals")
A second-year representative of the Morals Committee, Reiko begins monitoring the Mystery Research Club (especially Daisuke) after hearing rumors of disruptive activity. In spite of herself, she finds herself increasingly attracted to Daisuke, at least partially because she's spent so much time observing him she knows what a good person he actually is.
- Butt-Monkey: Reiko probably gets it the worst of any of the girls. Besides getting repeatedly hypnotized in her first few appearances, she's also wound up in several Not What It Looks Like moments, hit her head, and gotten embarrassed, Daisuke once saw her bare buttocks.
- Buxom Beauty Standard: While not as well-endowed as Kotone, Reiko has a pretty sizable bust. This is something Daisuke is well aware of.
- Catchphrase: "Immoral!"
- Covert Pervert: As much as she asserts that she's an upright student, Daisuke (and later the rest of the club) pick up on her fantasies quickly. Once she comes to terms with her feelings for Daisuke, she occasionally gets imagine spots that suggest she'd be willing to go along with any kind of fetish play he might ask for.
- Desperately Looking for a Purpose in Life: After her duties in Public Morals are temporarily suspended in Chapter 168 ("The Mystery of Revoked Qualifications"), she confesses to Daisuke that she feels worthless as a normal student.
- The Dreaded: She's actually quite effective as a member of the Public Morals committee, and is generally able to shut down any shenanigans by yelling at the perpetrator.
- Everyone Can See It: As far as the Mystery Research Club is concerned, it's fairly obvious that the inside of her head is much, much, much more indecent than anything that actually happens.
- In terms of her feelings for Daisuke, Ryouko teases her about how obvious she is, while Chiaki instinctively sees her as a rival of sorts for Daisuke's attention.
- Imagine Spot: Has a habit of perverting everything and everyone she comes across in her mind, which other characters appear to be aware of and actively comment on.
- After accepting she's fallen in love with Daisuke (or at least finds him attractive), she occasionally has imagine spots that suggests she's not above indulging him if he has any... "interesting" kinks.
- Logic Bomb: Having to do something "immoral" because it's part of some sort of rule causes her brain to glitch.
- Love Epiphany: Has a number of smaller ones as the series goes on, to the point she's pretty much accepted she's fallen for Daisuke. As an example, in Chapter 234 ("The Mystery of the Lead Up to Summer Break") she notes to herself that despite other students being excited for summer break she herself feels gloomy and can't put her finger on why. When Daisuke greets her, it suddenly clicks: she won't be able to see him at all during the break. She scrunches up her courage to exchange contact details with him, and is seen walking around with a dazed smile and Luminescent Blush... until she bumps into the Morals President who confiscates her phone.
- Paper Tiger: While she's quite vocal about "immorality" going on around her, she's easily flustered if it's directed to her (Daisuke does this by complete accident in Chapter 74 ("The Mystery of Impressions"), while Tanaka teases her repeatedly about her feelings towards Daisuke).
- Reasonable Authority Figure: She tries to be this when someone tries to explain themselves, but her Covert Pervert tendencies tend to get in the way.
- Sour Prudes: It's sometimes shown that she's actually kind of jealous of how easily other girls get close to Daisuke. When she was temporarily suspended from the Public Morals committee, she came very close to telling Daisuke how she felt about him (since she no longer had to worry about her position as a member of Public Morals).
- Stalker without a Crush: She's taken it on herself to monitor the Mystery Research Club's suspicious behavior (and is officially asked to do so after her reinstatement in Chapter 168 ("The Mystery of Revoked Qualifications")). Subverted in Daisuke's case, as she develops feelings for over the course of the series.
- Stupid Sexy Friend: There are times when Reiko really, really hates the fact she finds Daisuke attractive, since it often throws her off her Public Morals game.
- Throw the Dog a Bone: Despite generally being a Butt-Monkey, she's easily the girl with the closest relationship with Daisuke outside of his clubmates. In addition, Daisuke's little sister Yui quite likes her thanks to sharing a love of dogs.
- Tsundere: Type A when acting as a member of Public Morals; she usually flips to a Type B when she encounters Daisuke outside of her duties.
- Yank the Dog's Chain: Just as she seems to be getting closer to Daisuke, something usually crops up to ruin it. For example, in Chapter 210 ("The Mystery of Freezing") she imagines Daisuke helping her to school the way he is for Kotone and Ran (both of whom sprained their ankles thanks to the icy roads). She then slips and bangs her head on a nearby tree badly enough to start bleeding, prompting Daisuke to take her hand and begin escorting her to school. Alas, Asahi-sensei chooses that moment to pull up in her car and insistently takes her to hospital.
Tanaka Ryouko
Tanaka Ryouko
School Year: First
Club: Go-Home, has part-time job at Cafe Marcott
First Appearance: Chapter 66 ("The Mystery of Total Coverage")
A first-year student who sits next to Daisuke in class, and is later employed at Marcott, the same cafe he used to work for. Is a Gyaru.
- Book Dumb: Is not a particularly good student. In fact, she's the only member of her trio of Gyaru pals who is in actual risk of failing and having to attend remedial classes.
- Didn't Think This Through: Sometimes happens to her when she acts flirty to Daisuke, but he responds with the utmost sincerity.
- The Gadfly: She sometimes does things for no other reason than she thinks it'd be amusing. For example, in Chapter 158 ("The Mystery of Couples") she gives Daisuke and Reiko a cake to share, then claims that it's the rule that a boy and girl who share the cake have to feed each other (which she knows that Reiko will follow no matter how embarrassed she gets).
- Gyaru Girl: Her blond hair, makeup, and short skirt are typical of the Kogal style.
- The Nicknamer: As part of her Kogal image, she often gives and refers to other characters with nicknames, such as Mo-chan (short for Morals-chan) for Reiko or Dai-chan for Daisuke.
- Oh, Crap!: Immediately panics when the Mystery Research Club shows up at Marcott in Chapter 106 ("The Mystery of Cafe Reunions"), as her employment relies on her school not finding out she's working.
- The Tease: Mostly towards Daisuke, although she occasionally teases Reiko as well.
Hayasaka Ran
Hayasaka Ran
School Year: Second
Club: Track Team
First Appearance: Chapter 53 ("The Mystery of Club Competitions", as unnamed member of Track Team), Chapter 73 ("The Mystery of The Track Team", proper introduction)
A sporty girl and member of the school Track Team, she was so impressed by Daisuke's running performance during the school's athletic meet she tries to recruit him into the Track Team. Despite Daisuke confessing that his performance during the meet was thanks to Kotone hypnotising him into going beyond his normal limits, she genuinely thinks he has a lot of potential.
- Graceful Loser: When she and her teammates are beaten in a relay race by the Mystery Research Club in Chapter 53 ("The Mystery of Club Competitions"), instead of being upset she and her teammates all but beg Daisuke to join their Track Team.
- After her second attempt to convince Daisuke to join the Track Team fails, she's been true to her word and not tried scouting him since.
- Honor Before Reason: She and the Track Team challenge the Mystery Research Club to a relay race in an attempt to recruit Daisuke. Since the Track Team now know what to expect, they take precautions against them (e.g. the member going up against Suzu wears multiple talismans to ward off evil curses). After the Track Team wins, the Mystery Research Club are bidding Daisuke farewell and wishing him luck in the Track Team until Ran points out that the terms of their challenge were that Daisuke would consider leaving the Mystery Research Club to join them. Daisuke declines, feeling his place is with his clubmates. After they leave, Ran collapses to her knees, having thought for sure the competition would get his blood pumping and get him to join them of his own choice.
- Innocent Fanservice Girl: Her running outfit is basically a very short tank top and very, very short running shorts.
- O.O.C. Is Serious Business: When she requests a leave of absence from the Track Team and claims she's weary of running, Daisuke refuses to believe that someone so passionate could just stop. In a role reversal of Chapter 73 ("The Mystery of Track Team") he's now the one who pops up to challenge her to impromptu races while she repeatedly turns him down. At least... until he pointblank tells her he can't believe she'd want to stop running, and in response, she grabs onto him to admit that she really, really wants to run.
- Spirited Competitor: She loves to run, and for some time she is absolutely certain Daisuke would put up a great match if only he'd leave the Mystery Research Club and devote himself to some training.
- In the rematch relay, she freely tells them to use hypnosis, since it's only fair the Mystery Research Club use all of their unique skills to counter the Track Team's obvious ability in running.
- Stalker without a Crush: Unlike many of the girls in the series, Ran has no romantic interest in Daisuke at all. The only reason she insistently followed him around for a time was because she genuinely thinks he has the ability to go far in the Track Team and feels he's squandering his potential in the Mystery Research Club.
- Stupid Sexy Friend: In Chapter 277 "The Mystery of Rag Cleaning", Daisuke gets roped into joining her in an impromptu race (ostensibly because they're wiping up the rain-splashed corridor). He initially doesn't plan on putting much effort into it, until he realises that when behind her he has a really good view of her well-toned legs and can almost look up her skirt. In order to avoid being seen as a pervert, he quickly outpaces her.
Kaname Yoshizawa
Kaname Yoshizawa
School Year: Third
Club: Newspaper Club
First Appearance: Chapter 38 ("The Mystery of the Newspaper Club")
The head of the Newspaper Club. A dogged journalist always on the hunt for scoops, she originally took interest in the Mystery Research Club when she happened to watch them repel a bear in Chapter 36 ("The Mystery of The Bear"). However, after realising that Daisuke is a Weirdness Magnet, she decides to focus more on him (much to Daisuke's own dismay).
- The Dreaded: Chiaki describes her as being feared for her ability to sniff out people's dirty laundry, giving examples of the time she exposed the Baseball Team manager's two-timing or the Photography Club's sneak photography.
- In Chapter 66 ("The Mystery of Total Coverage"), she blatantly sits in Ryouko's place in order to stick to Daisuke as part of her "total coverage". Daisuke protests and tries to draw the attention of their homeroom teacher, who looks away and claims he doesn't see the problem, since it's clearly Ryouko sitting there.
- Exact Words: Like any good paparazzo, Kaname doesn't lie. She prefers to use exact words. For example, in Chapter 225 ("The Mystery of Idols") she publishes an account that claims that Daisuke referred to Nonoka as his girlfriend during their trip to the beach in Chapter 138 ("The Mystery of Getting Hit On"). She simply omits the context: it was a Boyfriend Bluff to get some aggressive pickup artists to leave Nonoka alone.
- Hot Scoop: She's attractive in her own right, as seen when Kotone hypnotises her into wearing a bunny suit in an attempt to get blackmail material they can use to keep her away.
- Indy Ploy: In her first appearance, Kotone hypnotises her into wearing a bunny suit in order to have some blackmail material to use against her. She immediately offers Daisuke (who was holding the picture of her in the bunny suit) a very saucy picture that had earlier knocked Reiko out do to how spicy it was. Daisuke immediately complies, and Kaname makes her escape with the bunny girl picture while Daisuke is rightfully smacked by Chiaki.
- Jerkass Genie: In Chapter 225 ("The Mystery of Idols"), Daisuke seeks her help to control Nonoka's sudden popularity when she's seen without her glasses. She asks if he's sure he's okay with whatever she does to do so, and he agrees. Cue the next day, and the Newspaper Club publishes a scoop that he and Nonoka are dating (using a picture of the two from Chapter 138 ("The Mystery of Getting Hit On") to sell the illusion). It works and puts an end to Nonoka's brief period of being a school idol... but also results in many very unhappy boys hunting Daisuke down.
- No Sense of Personal Space: She has no problems coming right up to Daisuke, and when she tells him she'll be shadowing him as part of her "total coverage" she is true to her word and follows him around.
Family Members
Goryou Family
Yui Goryou
First Appearance: Chapter 19 ("The Mystery of Nursing")
Daisuke's little sister. A middle school student who becomes close to Suzu.
- A-Cup Angst: Accidentally inflicts this on Suzu, who notices Yui actually has a surprisingly full chest despite Yui being much younger. Suzu actually has a minor Heroic BSoD when she realises that Yui will actually grow larger than her.
- Annoying Younger Sibling: Daisuke sometimes treats her as this, usually when he's embarrassed. Otherwise, he dotes on her.
- Dull Surprise: Yui isn't really fazed by the Mystery Research Club's antics, and quickly reassures Suzu that she doesn't mind her love of the occult after seeing her room.
- Genki Girl: She's very cheerful and energetic. This is actually part of the reason Chiaki's little brother Kenta has a crush on her.
- Innocent Innuendo: When she learns Suzu had slept over (and in Daisuke's room), she declares "I wanted to sleep with Suzu-chan too!"
- When their mother thinks that Daisuke is cheating on Suzu with Asahi-sensei, Daisuke tries to get Yui to clarify just what his relationship to Suzu is (clearly expecting her to say she's a good friend). Yui instead happily mentions that "Onii-chan and Suzu-chan are so close they even sleep together!"
- While giving Kenta advice about trying to get Daisuke and Chiaki together, she also mentions that "I won't lose either!", which Kenta interprets as her being yet another love rival for Daisuke.
- Shipper on Deck: Towards Daisuke and Suzu.
- Sibling Yin-Yang: Daisuke is generally pretty lethargic and would prefer to take the path of least resistance, while Yui is energetic. While Daisuke is reasonably fit, Yui is pretty sporty. Daisuke will often react to the craziness around him, while Yui just takes things as they come.
Megumi Goryou
First Appearance: Chapter 57 ("The Mystery of the Supermarket")
Daisuke and Yui's mother.
- Absurdly Youthful Mother: She looks really, really good for someone who has a high school aged son and a middle school aged daughter. In Chapter 286 ("The Mystery of Saunas"), Asahi-sensei tries to learn the secret of how she looks so youthful.
- Mum Looks Like a Sister: Due to how youthful she looks, people who see her with Daisuke either wind up thinking she's his lover (like Reiko does as mentioned below) or that they're relatives who're close in age.
- Relative Error: When Reiko Takahama happens to catch sight of Daisuke and his mother shopping in Chapter 57 "The Mystery of the Supermarket" and overhears them discussing dinner, she believes they're lovers living together. Alas, she also thinks that Daisuke's mother is a cross-dressing boy.
- Retired Badass: It's mentioned that she was a former ace of the Running Club back when she was in high school. She's still got it, considering that she easily outpaced several high schoolers when she was mistaken for a cross-dressing Daisuke during a sporting competition (long story).
- Strong Family Resemblance: Characters mention that when properly dressed up, Daisuke closely resembles her. In fact, when Reiko Takahama stumbled upon a cross-dressing Daisuke (it's complicated) and later met Daisuke's mother, she thought they were the same person.
- Sustained Misunderstanding: She was under the impression Daisuke and Suzu were dating since Chapter 23 "The Mystery of Ghost Photography". It's hard to blame her, since Suzu even spent the night at their house.
Daisuke and Yui's father
First Appearance: Chapter 304 ("The Mystery of Catch")
- Amazingly Embarrassing Parents: Daisuke outright describes his dad as being a pain. Part of it is because like Yui, he's quite sporty and dragged Daisuke out of bed when all Daisuke wanted to do was laze around for New Year's.
- Covert Pervert: Very downplayed, but he doesn't mind the sight of a slightly sweaty, out-of-breath Kotone.
- Like Father, Like Son:
- Daisuke evidently got his Made of Iron aspect from him, as he laughs off a baseball to the face.
- Yui meanwhile seems to have gotten her Genki Girl personality from him, as he appears to be quite sporty and boisterous.
- Made of Iron: When Kotone accidentally hurls a baseball into his face, he laughs it off with a slight nosebleed, and praises the strength of the throw.
Kanda family
Chiaki's siblings
First Appearance: Chapter 58 ("The Mystery of the Kanda Family")
- Anime Hair: Kenta's hair spikes similarly to Takeru Aizawa from the author's previous work, although his isn't quite as unrealistic.
- No Name Given: None of them are given names except for the bandage-wearing boy, Kenta, who is named in Chapter 143 ("The Mystery of Bottle Rockets").
- Satellite Characters: They only appear alongside Chiaki and have little characterization, although Kenta starts getting more emphasis from Chapter 119 ("The Mystery of Jungle Gyms") onward when he begins actively pushing Daisuke and Chiaki together.
- Shipper on Deck: For Daisuke and Chiaki; Kenta in particular plays matchmaker in order to get closer to Yui.
Chiaki's mother
First Appearance: Chapter 58 ("The Mystery of the Kanda Family")
- The Faceless: Her face is blocked by Chiaki's hair in the one frame she appears.
- No Name Given: Like the majority of Chiaki's family, her name isn't revealed.
