Nagi is a petite girl with wavy shoulder-length blonde hair and brown eyes. She wears a sukajan jacket with white stripes over a blue seifuku uniform, and brown shoes. Her style is best described as sukeban. No matter the season, Nagi is always seen wearing a pair of black tights. This is mainly due to hiding the scars she received from her abusive father.

As an adult, she ties her hair up in a ponytail and wears a simple shirt and skinny jeans. She's usually seen wearing convenience store or grocery work clothes.

In her middle-school age, Nagi used to be grumpy and ill-tempered. Due to her father’s abuse, she took on a delinquent image, gradually developing a strong, tough personality to cope with her issues. However, when Rikako befriended and helped her, she significantly changed into the person she is in the present.

Thanks to Rikako’s influence, Nagi became a fun-loving, warm-hearted and tough girl who always tries to get thrills out of something, even when things get tough. Though due to her rebellious nature, Nagi can get mischievous and is particularly eager about the gang system. While she can be straightforward, very short-tempered and aggressive, Nagi is extremely protective of those she cherishes and is willing to participate in fights just for their sake. On the other hand, she is frigid and hostile to those who get on her nerves ; mainly Moebius.

In 2017, Nagi has significantly mellowed down from her middle-school self ; she is much more diligent and cool-headed, gaining a strong amount of wisdom, though she can accidentally slip back into her delinquent mode under any circumstances.

Fighting Prowess 

Nagi has efficiently honed her fighting skills with self-taught training, making her a competent and strong fighter, though not on the same level as Mikey's. In spite of her petite build, her fighter skills were adequate and intimidating enough to initiate fear in the upperclassman and her opponents. 

While her thrill-seeking personality and passion are her greatest strength in battle, it can be also exploited as a weakness by her opponents to make her miss and perform sloppily. Nagi's fighting style is mainly hit-point tanking without bothering with either strategy or temperance, making her moves predictable and leaving her open.

Embroidery

In her spare time, Nagi likes to do embroidery as a stress-reliever. She is excellent at crocheting and knitting, as well as making intricate and eye-catching decorations in public. She even embroidered the Tokyo Manji Gang symbol on several handkerchiefs she gave to her friends. 

The name Nagi means "kite" (凧), while her surname Kuroha means "black" (黒) and "blade" (羽)

• Her character personality and story were mainly inspired by Chloe Price (Life is Strange), Dorothy (Princess Principal), Masuki Satou (BanG Dream!), Rika Kawai (Wonder Egg Priority), Yang Xiao Long (RWBY) and Arisa Uotani (Fruits Basket)
• Her favorite food is natto, while she dislikes mi goreng.
• Nagi likes dogs, sukajan jackets, action manga, and nail polishes, while she dislikes waking up early (especially being disturbed from her sleep) badly cooked food and newts.
• Her theme song is "Spark Again" by Aimer.
• Mikey and Draken describe her as "tough as nails with serious lady balls."
• Nagi's hobbies consist of embroidery and training herself in self-defense.
• Her voice actress in English is Anairis Quinones.