TV-Series
Description
Kento Nanami is a 27-year-old Grade 1 jujutsu sorcerer who stands 184 centimeters tall. He has Danish ancestry, contributing to his tall stature and light blonde hair, and is recognizable by his signature green-tinted glasses and tan business suit, which he wears even while on duty.

Nanami's background is marked by a practical and disillusioned view of the world of sorcery. While a student at Tokyo Jujutsu High, he was an underclassman to Satoru Gojo. During his school days, he was close friends with his classmate, Yu Haibara. The trajectory of Nanami's life changed forever when Haibara was killed on a mission that had been misclassified as being less dangerous than it actually was. This tragic event led Nanami to believe that being a jujutsu sorcerer was a terrible profession, and after graduating, he left it behind to pursue a conventional life as an office worker at a financial company.

After several years working in a corporate environment, Nanami became equally disillusioned with the working world, finding that labor was also a miserable experience. Reasoning that if both paths were equally unfulfilling, he might as well choose the one for which he had a natural aptitude, Nanami made the logical decision to return to his former life as a jujutsu sorcerer. This pragmatic outlook defines his personality. Nanami is mature, calm, and strictly professional, often described as the most adult-like adult in the series. He has a strong aversion to overtime work, a direct consequence of his time as a salaryman, and this preference even influences how he fights. Despite his stoic and often weary exterior, he possesses a profound sense of responsibility and a quiet, unwavering moral compass, particularly when it comes to protecting the next generation of sorcerers. Nanami is also known to be a heavy drinker.

His primary motivation in the story is to carry out his duties as a sorcerer efficiently and to ensure the safety and proper development of younger allies. He is entrusted by Satoru Gojo to be a direct mentor to Yuji Itadori, a role he takes very seriously. Nanami becomes one of Yuji's most trusted and impactful teachers, teaching him not only combat techniques but also the harsh responsibilities and emotional weight of being a sorcerer. His most significant personal relationship is with his deceased friend, Haibara, whose death continues to haunt him and serves as a key reason for his initial departure from the jujutsu world. Seeing the wounded assistant director, Kiyotaka Ijichi, during the Shibuya incident triggers a quiet fury in Nanami as it reminds him of the senseless death of his friend.

Nanami is a model example of a Grade 1 sorcerer, possessing exceptional combat skills, tactical intelligence, and leadership abilities. His primary innate technique is the Ratio Technique. This ability divides the length of any target, whether an enemy's body or an inanimate object, and forcibly creates a weak point at the 7:3 ratio point. Striking this precise point triggers a critical hit, allowing Nanami to inflict significant damage even on more powerful opponents. The technique is versatile and can be used with his blunt sword or his fists.

He also utilizes a unique binding vow related to his salaryman past, which he calls Overtime. During regular working hours, he suppresses his cursed energy output to around eighty or ninety percent. However, once his self-designated work hours are over, he can invoke "Overtime," unleashing one hundred ten to one hundred twenty percent of his maximum power. This vow perfectly reflects his personality and his disdain for working past quitting time. Nanami is an expert in hand-to-hand combat and swordsmanship, and he is particularly renowned for his proficiency with the Black Flash, a distortion in space that occurs when cursed energy is applied within a fraction of a second of a physical hit. He once held the record for the most consecutive Black Flash activations in a single day, a record later broken by his student, Yuji Itadori.

Over the course of the story, Nanami serves as a crucial supporting figure, providing stability and experience in high-stakes situations. He fights against the dangerous cursed spirit Mahito, managing to escape their first encounter unscathed after collapsing a building on him. He is later a key participant in the Shibuya Incident, where he demonstrates his leadership by organizing the other sorcerers after Gojo is sealed. He battles the special grade cursed spirit Dagon alongside Naobito Zenin and Maki Zenin. After being severely injured by the special grade curse Jogo, a battered and exhausted Nanami continues to fight, protecting civilians from transfigured humans. He is ultimately killed by Mahito in front of a horrified Yuji Itadori. Creator Gege Akutami has stated that while he did not want Nanami to die, there was no way around it for the sake of the story and the development of Yuji's character.