Even the Girls Want Her: Our first treatment started when she aggressively saved two girls from an incoming football kicked by two schoolboys. The result: the girls look up (with heart-shapedeyes, people!) to her like a manly prince.
Urban Legend Love Life: Riko tried to correct her first witness of Natsuo's romantic rehearsal early on, which led Natsuo to think that Riko used to have boyfriends in the past. Riko subtly tried to deny such a conlusion, but Natsuo put so much faith in her that she, in fear of disappointing Natsuo, continued lying about her status. Ever since, she became Natsuo's reluctant love life advisor, who then spread the word to people like Suzune, much to Riko's chagrin.
The Ace: She's a top-notch student at The Fujisaki Girls' Academy who has some incredibly good grades, charismatic people skills with the teachers and efficient human resource managing. Riko mentions that Maki is so impressive that she could do all of this at once at no penalty to her overall performance - in Riko's words, "a super middle schooler".
Amazingly Embarrassing Parents: Her dad runs a lingerie company, and appeared in a commercial extolling various womens' undergarments in song. She's very sensitive about it.
Cloud Cuckoo Lander: She pulls some really Insane Troll Logic out of nowhere in what should be ideal circumstances in a romantic encounter. This causes her otherwise normal behavior to turn eccentric, and turns off at least two of the guys at the cram school as a result.
Even the Girls Want Her: Due to her intelligence, kindness and beauty. She gains the same reaction Riko gets from their fellow schoolmates.
First Name Basis: When a boy uses her last name without honorifics, she completely panics, acting like he stole her Sacred First Kiss, and falls into a Heroic BSOD. She had, of course, envisioned some insane romantic scenario in which a guy she'd been dating for months would finally use her last name without honorifics. She apparently can't even imagine what would make a guy worthy of using her first name.
I Just Want to Have Friends: Prior to meeting Riko, she was largely self-reliant. Then when Riko greets her friend Mika in the hallway, Maki has a sad look on her face at seeing how friendly the two girls are. Later on, after she finds out that Riko lied about being an expert on love, she was more distressed at the fact that Riko wanted to quit the student council and probably not spend any more time with her, than the fact that she lied. At least until the latter gave a heartfelt apology, stated she didn't want to quit, and declared them to be best friends.
Lonely Rich Kid: Although she doesn't flaunt her riches, her father is a successful, if somewhat embarrassing, businessman, and kept her away from boys her age. This may help explain why Maki has such weird ideas about guys in the first place, particularly after her mother accidentally reads some of her love lab notes and convinces him to loosen his grip on her upbringing a little, lest some smooth talking playboy exploits her naiveness.
Student Council President: In effect, to the extent that most students think she's the president, but technically she's the vice-president.
Sweet Polly Oliver: Riko jokes that it'd be easier to study if a hot guy was encouraging her...so Maki dresses up as one.
Terrible Artist: Her body pillow has a crude caricature of a male student on it, in stark contrast to the more conventional Bishounen or Hunk. For the sake of Rule of Funny, her romance fantasies involve meeting a living version of her absurd artwork.
Blind Without 'Em: She actually tripped on her own feet after the girls take her glasses away briefly to change her look for a date.
Brutal Honesty: She often says it like she sees it, which doesn't go over well with Riko a lot of times.
Can't Get Away with Nuthin' : She meets up with her secret boyfriend once, outside of school. A member of the shady newspaper club wanders by and takes a picture, accidentally reveals it to the teachers, and Sayori is nearly kicked out of the student council.
Jerk with a Heart of Gold: As much of a Jerk Ass she can be at times, she does have moments where she's nice and does things without an ulterior motive, such as when Maki's love lab notes were accidentally distributed at a student council meeting. Sayo claims that said notes were research for a question given to them anonymously by a student, and they all accept that excuse, since they're unaware of Maki's Cloud Cuckoo Lander tendencies.
Money Fetish: She openly admits to Yuiko that it's money she likes, not the accounting work that comes with the treasurer position and worse, obsessed with controlling the fundings of people she can manipulate.
Only Sane Woman: In the sense that she's the only one in the student council who doesn't fall for Riko's lie.
Riches to Rags: She was transferred out from Fujisaki Academy to a public school when she was in her fourth grade because her parent's business went under.
Unlucky Childhood Friend: Implied to be one towards Riko. The truth is a bit mixed, as Satoshi and Riko were somewhat close when they were younger, and later on he admits to Maki that he did have a crush on Riko. Whether that was a lie to cover for Riko, or a truth, considering he did run away after hearing Riko rejected him, is uncertain.
Smart People Wear Glasses: Incidentally, he was also the one who was forced to tutor Riko so that she could attend Fujisaki, which seems to have high academic requirements. When he tells Maki about it, he seems really resentful about it however.
The Student Council President of Minami Middle School's Student Council.