Hayase Nagatoro is one of the two main characters of the Don't Toy With Me, Miss Nagatoro manga series. She is a high school student who likes to tease and bully her Senpai, the other main character, although she secretly harbors strong feelings for him. Nagatoro is an energetic, athletic, popular and rather sadistic - but deep down very sweet - girl, often referred to as a "sadodere". She is part of a 'cool kids' clique together with her friends Gamo-chan, Yoshi and Sakura, and is a member of the swimming club, despite also having a liking for martial arts such as muay thai, boxing, capoeira and especially judo whom eventually lead her to join the judo club as well. Her friends affectionately call her with the pet name "Hayacchi". Nagatoro is an attractive, petite and short statured high schooler with long, straight black hair pinned to the right side with a pair of white hair clips. She has brown skin with noticeable - though sometimes inconsistent - tan lines in the shape of her swimsuit, and large, expressive amber-maroon eyes. She has a metallic piercing on her upper right ear and both of her lobes are pierced, despite this she rarely wears earrings. Compared to other characters, she is exceptionally small, although it has been hinted that she may have a late growth spurt and she actually grew several inches during winter. Nagatoro has a lean, athletic, slender and very flexible physique with a modest bust size which she is often ashamed about despite being - considering her size and build - pretty average sized; also she seemingly gained a bra cup as the story progressed. Nagatoro is rarely seen without a sadistic, cocky, smirk that often displays her very prominent canines and has the tendency to widen the pupil of just an eye whenever she grins. She typically wears her school uniform consisting of a white button up shirt (whose sleeves and collar she never keeps buttoned) and a navy blue skirt completed with a pair of sneakers and no socks. However, in summer she wears a short-sleeved shirt in her uniform, while in winter she is shown to wear a light brown sweater, black thigh-high stockings, loafers and occasionally a blue blazer. She is also often seen wearing the light blue and white swimsuit of her club. When not at school she usually sports a simple, practical or tomboyish choice of clothing unlike most of her friends; however she has proven to know how to relatively dress up if needed. Nagatoro comes off as energetic, cheerful, sarcastic, flirtatious, prone to fast-talking and moving individual with a sadistic streak. She likes to bully Senpai and finds joy in teasing him, however, although she appears to just want to torture him, there seems more to it than that. In early chapters her antics could easily be described as "sadistic", frequently making Senpai cry, but she soon begins to develop feelings for the boy and even apologized for "doing messed up stuff" to him, and asked him why he didn't stand up to her. Since then her bullying has mellowed out, and she even frequently acts outwardly friendly to Senpai, despite continuing to call him a "creep". As time passes, she occasionally defends Senpai's dignity and is even shown to be very concerned about Senpai getting angry at her as well as being sincerely sorry for going too far. Nagatoro is very much a tsundere, despite denying her crush for Senpai and frequently mocking him. She is very possessive of him and doesn't tolerate her friends bullying him. Despite frequently belittling him, she does care greatly for Senpai, being quite bothered when he says that "all he can do is draw" and getting motivated/angered enough by his lack of self confidence to begin personally training him. She also enjoys Senpai's company very much, but rarely outwardly shows it. Albeit when she invited him to the beach or to her house, she shows her intentions to enjoy it and wanting to do it again sometime. However she reacts extremely flustered and nervous whenever he does the same, for example her face wearing an expression of extreme shock when Senpai joked about failing a grade to spend more time with her, although she was angry when he did not fail, saying "Do you hate spending time with me that much..?". She is very good friends with Yoshi, Sakura and especially Gamo-chan, whom could be considered her best friend, despite their similar and often competitive personalities sometimes putting them at odds in a sort of friendly rivalry. Also, Gamo-chan loves to tease her in order to make Nagatoro admit her feelings for Senpai and bring them closer, causing pranks that sometimes led the two to resort to near-physical violence, despite that they seemingly always made peace rather quickly every time they fight. Moreover, judging by their friends' reactions whenever Nagatoro and Gamo-chan butt heads, it's not wise to make them mad, implying that they both have a temper warranting fear. Although very popular among boys, with several of them often attempting to hit on her or her friends, she always rejects them and showing herself to be bored, contrarian and standoffish while talking to them, even to the point of saying to Yoshi that "boys are boring", despite her obvious growing crush on Senpai. Her occasional coyness seems to be for Senpai alone. It's implied that Nagatoro uses casual rudeness towards Senpai in order to deflect her real intentions, taking three steps in with her suggestions ("let's wear matching yukatas for next year's festival"), and two steps out with her teasing ("I'm joking, that would be gross"), inching herself gradually closer to him, thus defusing the situation for the moment while leaving a kernel of hope for Senpai. It's also shown that Nagatoro is a sweeter and more empathetic person than she lets on, and that she's more susceptible to Senpai's kindness than he realizes, even tenderly hinting to him - when he gives her his mail contact, all while telling her that he's not a person worth talking to - that his declarations of self-deprecation affect her too. Also, she has a deep sensitivity toward the arts, whether is movies, paintings, dance, poetry or music. She seems to genuinely enjoy Senpai's art, frequently encouraging him to draw more and forcing him to use her as a model for his art. Although, whether or not it's to train him to draw the female body, get him to draw her specifically, or is just an excuse to spend time and tease him more, is unknown. Nagatoro herself also occasionally draws. Despite very frequently making sexual jokes to Senpai, mocking him for being a virgin and calling him a pervert, she is very nervous and sensitive about sexuality. For example: when Senpai was giving her a piggy back ride and his hand slipped to her upper thigh, she proceeded to jump off and ran away with minimal explanation and a nervous and terrified expression on her face, when Senpai meant to push her in the elbow and instead hit her breasts, she was very outwardly shocked and embarrassed for a couple of seconds, she had no problem in riding senpai like a horse for "muscle training" until when two unnamed girls saw it, making her very self-aware and causing her to immediately jump off, when she accidentally facetimed Senpai in the bath, she screamed in terror, when she and Senpai were trapped under a gazebo during the rain and he saw her drenched clothes and bra, she instantly blushed in frustration, almost all those times, however, Nagatoro recovered after a couple of seconds and started again to accuse Senpai of grossness and sexual perversion, although he eventually realized that Nagatoro would be at a loss if he actually respond to her taunts romantically, and Nagatoro is all bark and no bite, especially due to the fact that she can get as embarrassed as he does. The hypocritical humor of Nagatoro constantly teasing Senpai about being a virgin is that she's obviously as inexperienced with physical intimacy with the opposite sex as he is. Nagatoro has a complex for her bust size and appears to be very self-conscious as well as jealous and possessive. In the beach chapter, when Gamo-chan and Yoshi were harassing Senpai with their large boobs, Nagatoro get frustrated, took off her clothes as well, stood in a bikini in front of him and demand Senpai to go buy drinks. She also was mortified when learning of Gamo-chan's prank to have Senpai "molest" her boobs - due to her jealousy since she is the least buxom among her friends - but nervously laughed it off as an hilarious prank upon learned that she had stuffed anpan in her breasts and Senpai never actually touched them. It also appears her teasing is somewhat just a front, a coping mechanism to mask her insecurities and inner nervousness. She is also very athletic, loves the beach, is a fantastic swimmer and a superb skier as well as having a huge passion and proficiency in various styles of martial arts; she shows her willingness to train Senpai after his poor performance at a marathon and easily outpaces him during their training run. Apparently, Nagatoro doesn't like shoes, as she almost never wears socks and is frequently barefoot when she can get away with it.