Nagi is short in stature, she has long blond hair which is tied in two long twin tails and she has green eyes which she inherited from her parents. According to Hayate, Nagi looks like her mother. She wears a Hakuo uniform during school, while at home she is usually seen wearing modern clothing.
When she used her alter ego Mask the Money, she wears a mask to cover her eyes and a short frilled skirt with long thigh high socks and a long sleeved blouse with a huge ribbon. During New Years, she wears a yukata with different designs on it. Nagi always wears shoes with heels just to look tall and doesn't want others to call her "short" or "small".
Background and Personality
Nagi is short-tempered, spoiled, anti-social or socially withdrawn, hates to lose and to admit her faults, has a considerably hard time confessing her true feelings towards Hayate (but does confess in the last episode of season 3) or anything in the fact of the matter, she acts immature a large portion of the time but is ultimately a good, educated girl. She is good at finance and likes to learn. Her mind is possessed with her own. She cares for her family and friends, but she doesn't want to show her concern directly. She usually tends to show her concern with "formal words". She is a tomboy and tsundere hikkikomori princess.
Since going outside is very dangerous because of her status, Nagi favors staying at home. Not liking company in general, she lives away from her grandfather in a "small" (compared to the main Sanzenin estate) mansion with minimal staff. Despite her Otaku NEET-like lifestyle, she is intelligent enough to skip 3 grades at school, which even turns out to be one of Tokyo's most prestigious academies. She has an otaku-level hobby with manga, anime and video games, and draws her own manga which is called Millennium Legend: Magical Destroy. Her Otaku-level is high enough that she has submitted entries for multiple amateur manga competitions, though her entries never won. Her art is decent (she started drawing almost from when she was a toddler) but her sense of plot is incomprehensibly warped, not to mention her art style is odd at best. Her genres clash and she draws a magical girl story in the style of a Shonen Manga, Magical Destroy (read: very muscular, very masculine magical girl named Britney who behaves more like a samurai). Only her best friend, Isumi, and a wanderer ghost, Linn Regiostar, can read and understand her manga.
Because of her pampered existence, she lacks any worldly knowledge and is even incapable of looking after herself. In an episode, with the absence of both Maria and Hayate, she was shown to be incapable of even making a cup of tea on her own, wrecking the mansion in the attempt. Nagi is mortally afraid of the dark (due to an incident with Isumi), so she shares her bed with Maria in the nights. She also doesn't like swimming. While Hayate always reminded her to go outside and gather experiences on the outside world, she always thought that that will be boring or she always lost and risk being kidnapped. Which Maria always states to her that without Hayate she will always get lost or be in danger.
Nagi likes to do what she likes to do, but mostly what she likes to do is not so good for her future. She is so hard to control, that even Maria, who has lots of talents, can't control her. But Hayate, her average educated and insensitive butler, who saved her from the kidnappers and the mafia, is able to convince her to go to school, do exercise, have many friends, etc. He helps Nagi to be a better person. He saved both her life and her lifestyle. In short, Hayate is her savior.
Sakuya Aizawa is Nagi's cousin. Sakuya is a talkative, cheerful girl. Her first encounter with Nagi was on a party when Nagi was about 4–6 years old. Sakuya saw Nagi was gloom, so she decided to talk to her. Isumi Saginomiya is Nagi's best friend. Probably she is her best friend. Isumi is a quiet girl, who easily gets embarrassed. She met Nagi on party that held because Yukariko's health became better when Nagi was about 5–6 years old. Nagi showed Sakuya her manga and got insulted by her. Nagi threw her manga to a trash bin. She cried and decided to stop drawing manga. But Isumi picked it up, read it and was interested. She asked Nagi for the next chapter. Nagi was touched. Wataru Tachibana is Nagi's friend and fiancé. Wataru is a blunt, responsible kid. He owned a DVD rental in the middle of Tokyo. His first encounter with Nagi hasn't been explained. He had many fights and argumentations with Nagi.
- (About Maria [Chapter 149]) "Ugh...that Maria...minding other people's business."
- (About Hayate) "That boy, he can be so tactless."
- "Hayate's such a jerk for leaving me alone like this."
- (Referring to Himegami) "This guy is a total idiot."
- (Referring to Hayate) "Let's hire him as my butler for Himegami's replacement."
- "Hayate please stay with me, until the very end."
- (To Ayumu) "Just to tell you that Hayate belongs to me!"
- "Hayate, I hate you, I hate you, I hate you!"
- (To Hayate) "On your birthday I'll get you a watch, I'm making a solemn promise to that."
- (To Ayumu) "Of course, Hayate is my butler and he always saves me."
- (Referring to her mother) "I had a dream of her for a long time. It's been what, 8 years since she passed away? Well, I'm 13 now."
- (To her mother's grave) "Mother, this is Hayate Ayasaki, he's my new butler, isn't he great?"
- (Referring to the star that her mother pointed at) "Last time you told me the same story, you were pointing at Arcturus from Bootes."
- (To Hayate) "Enough of the height thing!"
- "I'm Nagi Sanzenin, do you want me to draw you a picture or something?"
- (Referring to Maria's outfit for the trip to Shimoda) "I don't think so, why don't you get out of those ridiculous PJs and go back to your maid outfit?"
- (To Tama when he was a cub) "I Nagi Sanzenin, will swear that I will be your mother until the very end. I will protect you, and look after you with all of my heart."
- (To Ayumu) "In other words, you have bad comprehension and suck at giving up, and so your grades are bad and you can't get over Hayate."
- "This is why I hate, hate going outside, because it's too dangerous."
- "I will be buying it with the money I save up from my part-time jobs, which I will be starting today!"
- "Why do we want to keep such huge and dangerous animals as pets?"
- (Referring to Hayate's joke) "Those who think you can get people to laugh with that should be born as toilet paper rolls in their next lives."
- (To Ayumu) "Stop bragging about being normal!"
- (To Maria) "I...I could have made tea for myself. But this time, I let my guard down a little."
- "But I'm not swimming, that's my final answer!"
- (To Ayumu) "As if, you idiotic hamster! What's wrong with your insane imagination?"
- (To Hayate) "I should call you whenever I feel like it, right?"
- (To Sakuya) "Here, I got you a present. It's your birthday, so I have to come."
- "Just as I expected, Hayate's been seduced by a strange woman."
- (While reading manga upside down) "The price of...pork bellies are...dropping fast."
- (Referring to Hinagiku) "In order to win this, I'll be competing her as well."
- (To Hayate) "If I compete Hinagiku Katsura, I'm dead. Find out what distance will she be running, would you?"
- (To Wataru) "I go where Hayate goes, mister. Even if ghosts or monsters attack us, I'm not afraid of anything! Anything at all!"
- (To Hayate) "Are you out of your mind? What kind of master would leave their servant? I thought I said, we're going to win this."
- (To Sonia) "You better have a good reason on wanting revenge on me!"
- (To her mother) "Mother, it's been eight years since you passed away.I have someone I love. We fight often, but we're enjoying our days together. I don't think I'll be joining you for a while, so please watch over me as the stars and the sky. Always...and forever."
- (To Hayate [Chapter 252]) "Words are imperfect. Putting it in words will just create misunderstandings. Words are the root of misunderstandings."
- "Forgiving someone and being forgiven. . .that's what binds people together."
- "Nagi" means "windless" or "calmness", which seems to be the contrast to Hayate, which means "gust of wind" or "squall". However, according to Nagi in a 4-koma on the cover of Volume 13, she was named as such because her mother "wished that she'd mow down ("Nagi") everything in this world".
- Nagi makes a cameo appearence in Zettai Karen Children anime, the same studio who produced Hayate the Combat Butler, in episode 9 and 26 with Hayate. In episode 33, Nagi appears again with Hinagiku,Chiharu, Risa and Miki.
- The chibi version of Shana (Shana-tan) appears as Nagi in the anime parody short Shakugan No Shana-Tanwith just Nagi's hairdo.
- Nagi and Shana are both voiced by Rie Kugimiya.
- Shana (as Nagi) even calls Yuji Sakai "Stupid Hayate!", as she refers to him as Hayate Ayasaki.
- Nagi is scared of dark places because Isumi made a mistake while trying to help her.
- According to Chapter 90 Nagi knows 8 different languages.
- Nagi is revealed to be biracial judging from a fan's twitter question answered on Kenjiro Hata's blog, which said that her father's hair was blonde and was not from Japan.