Nanami is a tall, well-built man with blonde hair styled with a neat part. Nanami has very thin eyebrows as well as small hazel-colored eyes that are usually covered by his signature sunglasses, which don't have arms that wrap around the ears. Befitting a former office worker, Nanami is usually fully dressed in a formal business suit. His usual suit consists of a blue dress shirt underneath a tan blazer with matching slacks and light shoes. Attached to his dress shirt, there is a holster that sheaths Nanami's blunt sword, hidden by the back of his blazer. He also sports a necktie that shares the same dotted pattern as the bandages around his blunt sword. After graduating from Jujutsu High and working for corporate, Nanami wore a vertical striped jacket over a white button-down shirt and dark-colored tie with white dots all over it, vertical striped pants, and black shoes. As a student, Nanami wore a normal Jujutsu High uniform. His hair was styled slightly differently when he was younger. Nanami is a very wise and reserved kind of man, often appearing so calm and indifferent that he comes off as stoic and aloof. He seems like the kind of person who's too serious about his work, but Nanami just knows how to separate sentimentalism from service. He's blunt and straight to the point in most conversations and doesn't care for impractical optimism or questions left open to interpretation. Additionally, Nanami is very avid and quick to express his irritation, either on his face or verbally with his words. Nanami is often very impatient. He hates working overtime and is very serious about not going a single minute over what's required of him. Beneath his tough exterior, Nanami is actually quite sociable and doesn't mind intelligent conversations. He's practical and overly serious to an almost comedic point on occasion as well. He claims he only became a jujutsu sorcerer because it's slightly less idiotic than being a salaryman. In the role of one of Yuji's mentors, Nanami is a very big contrast to Satoru, who is far more outspoken and easy-going. Yuji and Satoru describe Nanami as "gloomy" and the former didn't believe they would get along at first.