Nino Nakano/Relationships

Nino stated that she takes a liking towards delinquent type boys, especially those with blonde hair.

Maruo Nakano
Nino suspects that Fuutarou and her father have some kind of arrangement, which is why she disliked Fuutarou trying to tutor her sisters. She disliked her father's constant absence but has grown past this. It's heavily implied that at least part of her resentment is because she feels her father is too controlling in their lives and doesn't give them the freedom to pursue their own interests. After Nino remembers that he is one who often "scurries behind the scenes," she has become more accepting of him, though she still feels lonely to an extent that he is distant from the family.

Nakano Quintuplets
Nino's reason for hating Fuutarou is because she thinks that their home is only for the five of them. Nino is revealed to actually care for her sisters and is protective about them, hence her unnatural dislike towards Fuutarou. Nino tricked her father that all of her sisters passed. Fuutarou realize how much Nino's care for her sisters. Nino wants to have her ears pierced because her sisters' all had theirs pierced. While Nino is not around, the sisters' meals are in a mess.

Ichika Nakano
Ichika praises Nino's cooking. Nino looks up to Ichika as an elder sister but would even go against her if necessary, especially when it comes to the safety of her sisters. Nino is angry at Ichika's attitude despite the possible danger that may befall Itsuki.

After Nino noticed Ichika's feelings and declaration to be with Fuutaro, they become the most heated love rivals as Nino showed more awareness towards her.

Miku Nakano
Nino-Miku quarrel is first shown. Nino acknowledges that she picks on Miku earlier and feels bad about it. Ichika notes that Nino and Miku's dynamic is similar to cats and dogs. Miku labels Nino as someone who is too stubborn. Miku says that Fuutarou needs to use sincerity to deal with Nino.

Miku is the one who often bickers with Nino, due to their opposing personalities. Both of them often give blunt remarks towards the other's traits or behavior, which often causes both of them to argue with one another. Despite this, there is no rift between them, and both still care for the other. Nino would even help her out if she asks for it.

Miku reveals to Nino that she likes History and Sengoku Generals.

Yotsuba Nakano
Nino always brought bandages with her because someone in her family got injured all the time. During the fireworks festival, Nino warns Fuutarou to not have any ideas toward Yotsuba.

Itsuki Nakano
Nino is the one who usually wakes up Itsuki. Nino pairs with Itsuki for the Test of Courage.

Nino is often seen together with Itsuki doing activities such as having lunch or hanging out with each other. They even go through the test of courage together. Nino is shown to be concerned for Itsuki's well-being, even going against "Ichika" when Itsuki is missing from their group while skiing.

While the two seem to get along with each other due to their similar personalities, they also quarrel harshly when they disagree on something. After Nino goes too far in refusing to study, without any care for all the hard work Fuutarou is doing for them, Itsuki slaps her and demands that she apologizes, resulting in Nino slapping her back and the two running away from home. The others imply that this is not the first time they've fought that way.

Fuutarou Uesugi
At the beginning of the story, Nino is open about her hatred and dislike towards Fuutarou. She viewed him as an outsider and didn't want him to intervene with her beloved sisters. Unlike her sisters, Nino hardly ever addressed Fuutarou by his name, instead calling him as "you" or "him." Nino's first impression of Fuutarou is "someone persistent and not popular," while Fuutarou's first impressions of Nino is someone who is self-righteous. Later on, seeing as how Fuutarou was dedicated to tutoring the her and her sisters, Nino came to aknowledge how much effort he exerts and even defends him from her father, saving him from being fired after they failed the majority of their exams. It is also noted by Itsuki that following the exams and being tricked by Fuutarou that he was sick, she was merely angry and left instead of trying to kick him out. However, any progress Fuutarou made towards building a friendship with her were suddenly reversed after Nino blamed him for the fallout she had with Itsuki, yelling that she wished he "had never come into [their] lives."

Due to Nino's infatuation towards "wild boys" and her poor eyesight, she fell for Kintarou, unaware that he was Fuutarou under a wig. She has been shown to like Kintarou considerably, as she lied about the types of boys she liked to get closer to him and wished that he was there following the argument with Itsuki. However, after realizing Fuutarou was Kintarou and seeing his persistence to reunite her with her sisters, even under a wig, she became friendler to him. She expressed less anger towards him over her sisters and even invited him to sit next to her under the kotatsu. After realizing that her lingering feelings for Kintarou were actually towards Fuutarou, she ironically becomes the first one to confess to him.

After confessing to Fuutarou and having to repeat it again because he didn't hear the first time, she becomes very open to him and doesn't hesitate to exclaim her love for him in front of others. She is aware of her prior rudeness to Fuutarou and, knowing that she hasn't given him a reason to love her back yet, makes various attempts to be closer to him. She even changed her way of addressing to Fuu-kun, something that displeases Miku. Ichika notes that Nino's love for Fuutarou are like a runaway train, with her assertiveness being the most unpredictable out of the sisters. Despite her increasing assertiveness, she is willing to delay her own progress with him for things like Ichika's attempts to sabotage Miku's plans.