Appearance: Nano is noted to be extremely attractive, even among her peers. She has long, straight silver hair reaching to her hips, with her fringe going across her right forehead, and crimson eyes. Nano usually maintains a stoic expression, only showing emotion in rare situations. Nano is one of the taller members of Rentarou's Family, and is about the same height as Rentarou. She has a slim figure, and a large bust for her physique. Nano wears a sea-green necktie as her neck accessory instead of a ribbon. She also wears black tights, and black loafers. Personality: Initially, Nano comes across as cold and stoic. She believed in living life as efficiently as possible, and saw relationships as meaningless, hence, she felt uncomfortable when coming to terms with her budding feelings for Rentarou. As the series progressed, Nano slowly opened up to the rest of Rentarou's Family and became more comfortable with expressing her feelings. She even admits that she spends time with her other co-girlfriends not because they happen to be dating the same person, but because she genuinely likes them. Nano is also calm under pressure, and is able to solve almost any problem that comes her way with almost computer-like efficiency, earning her the epithet of the "A.I. girl". Intelligence: Nano is academically brilliant, placing first in her year with a perfect score in all subjects. She has an eidetic memory, able to remember most information that she has encountered, and is usually the first to come up with solutions when Rentarou's Family is faced with a problem. She only falters when her emotions overwhelm her logical thought processes, with her love for Rentarou and her closeness with Shizuka having especially strong effects on her ability to make sound decisions. Nano has been compared to an encyclopedia due to her vast repository of knowledge. Athleticism: Nano is one of the more physically strong girlfriends in the series. Some of her feats include breaching a door by wrenching the doorknob off barehanded, and fighting Mei Meido (a superhuman in her own right) to a standstill in a water pistol fight. She also has above average kinetic vision, able to predict the trajectory of projectiles coming her way, and calculate the best position to throw opponents off balance in close combat. Nano is also proficient at self-defense, and usually carries a box cutter on her person for such purposes. Beauty: Nano is noted to be extremely beautiful among her peers, especially by her senior and co-girlfriend, Mimimi Utsukushisugi. When the both of them are together, they emit an aura which is powerful enough to blind any who look upon them. Background: Rentarou first meets Nano on the day the first term exam results have been posted, when he returns to his classroom to retrieve his smartphone, and sees her studying by the window. He offers to go see the exam results with her, but she refuses, saying that she knows that she has the top position. Rentarou and Nano are then paired for an experiment in their science class. During the class, Rentarou attempts to make small talk with Nano, only to find that she is cold towards others, and sees interpersonal relationships as a waste of time. However, when Rentarou accidentally cuts his finger on a razor blade during their experiment, Nano breaks character and sucks on his finger to stem the bleeding. That night, Nano realizes she has developed feelings for Rentarou, and is unable to focus on her studying. She then confesses to Rentarou, expecting him to reject her so she can return to her old self. However, when Rentarou accepts her feelings, Nano rejects him, saying that she has no desire for a relationship and there is no way she will go out with Rentarou. Rentarou then convinces her to at least go on one date with him, before making her final decision. On their date at the amusement park, Rentarou brings a Polaroid camera to capture some of their moments together, and comforts Nano when she feels uncomfortable while on the Ferris wheel. After the date, Nano admits that she had fun, but gained nothing significant from their time together. Hearing that, Rentarou decides to burn their photos and treat the date as if it never happened. To his (and her own) surprise, Nano stops Rentarou from doing so. Rentarou then points out that this is proof that Nano has gained something so important during their date, she was afraid to lose it. Understanding that there are more important things she needs to experience in life, Nano confesses her feelings again, and Rentarou accepts, officially making her his fourth girlfriend. Relationships: Rentarou Aijou: Nano loves Rentarou's efficient way of taking care of each one, having collected data on this every day. Shizuka Yoshimoto: Nano seems to have a fairly close relationship with Shizuka, accompanying her to buy books. She's the one who sees the most. Nano always saves Shizuka while gust of wind blows her petite body away. It has been implied that Nano saw Shizuka more than just a friend, as she briefly tried to admit that she loved her in Episode 19. Though, it can just be a joke with the fact that the two of them are very close friends. Mimimi Utsukushisugi: When Nano was in middle school, she took part in the same beauty pageant as Mimimi. Nano won first place, and while Mimimi was disappointed in her loss, Mimimi accepted it and attempted to make friends with Nano. Nano, however, dismissed her entirely, stating that friendship was "meaningless". This caused Mimimi to resent Nano for two years, until they met again after Mimimi joined Rentarou Family. Mimimi rematches Nano again to a competition, with the stipulation that if one of them loses, one of them must leave Rentarou Family. Through Rentarou's efforts, the two girls tie, and Nano apologizes for dismissing Mimimi. The two girls are able to become friends after this. Meme Kakure: Nano gets along well with Meme, who taught her how to knit. Trivia: Nano has kissed and been kissed by Rentarou at least 35 times. Nano is a light eater, and her diet mostly consists of supplements. Nano has acrophobia (an irrational fear of heights). Nano is the first member of Rentarou's Family to stay overnight at his house. Nano finds having her head pat to be very pleasing. Nano's birthday, March 14th, is refers to her habit of reciting digits of the irrational number pi (π) to calm herself down. Pi is approximately 3.14, rounded to two decimal places / three significant figures.