Souichiro Nagi is the main protagonist from the Tenjou Tenge anime and manga.
A self proclaimed hoodlum, and the heir of the Nagi demon exorcist family. A first-year student, he has been fighting his whole life because of being picked on, due to his lineage and their potential to go out of control as well as their general strangeness. Because of the way he looked and acted, he had little experience with women his own age, until high school. He has problems expressing his feelings toward people, often acting detached or surly even to his friends and family.
In the XP4 fics, Souichiro is currently a member of the Heroes Coalition and is part of the Triumph Division. He also attends the Vanguard Academy as a student.
In the AWA fics, Souichiro is a student at the AWA Academy.
Souichiro is a young man with a spiky, blonde hair and yellow eyes. He is currently wearing a black button-up school jacket, black baggy pants and white & red rubber shoes.
Souichiro is a teen obsessed with fighting and takes a lot of pride in that. Ironically, he believes that fighting doesn't resolve anything, and fights more for fun than anything else. Initially, he is believed to have an average, or below average intelligence. He is very cocky and gets angered easily, and always has wise cracks. He isn't very good with being around girls, because he had little contact with them up until high school because they thought he was creepy.
Souichiro is a self-proclaimed thug, and has no real martial arts style. Later he does start to develop more skill and becomes a very formidable fighter.
In the "Golden Week" vacation, Souichiro learned from Maya the "Reverse Striking" or Uraate technique which has been called the Distance Striking technique in China. You delay the striking and strength of the blow. At the master level you become able to intensify the power at a location of your choosing.
He advances very quickly picking up advanced moves such as Uraate in a matter of days, even without knowing what he is doing. An example of his improvement is his recent battle with Hirohiko Myouun Kabane, when Ayabattled Kabane, she had to use all her strength and determination to hold her ground against him and still would have lost if he had not held back, Souichiro had no problem fighting against Kabane, in fact he fought against Kabane at his full power and still broke his armor rather quickly and easily, showing that he has gone far beyond even Aya's level of strength. It should also be noted that Kabane didn't even receive the full force of Souichiro's punch due to the fact that his sister made her servant jump in the way at the last moment. Had Souichiro's punch followed through, Kabane would most likely have been killed. As of now he uses pure force and intimidation to win his fights, as no opponent shown so far is able to last more than a single hit from him in his exorcist form. Souichiro also has unbelievable endurance and resilience, several times in the series he has suffered vicious beatings only to be perfectly fine the next day, and has been able to continue fighting after being hit with attacks that hospitalize others. Bob even mentioned that Souichiro could survive a fall from a third floor window. His physical strength even without his demon exorcist form is incredible as well, as seen when he broke several of Masataka's ribs with just one punch.
Despite claiming himself to be a thug, Souichiro's conviction as a fighter allows him to surpass the mental powers of people like Kago Sohaku. Among his numerous abilities, he has an ability to see into people's hearts and know what kind of people they are. This ranges from comical, using Aya's home-made bento as a shield in his primer fight with Masataka, to understanding that the basis of his own father's techniques and strategies were based on his immortality and his fear of those like Souichiro, who were stronger than him.
- Before getting in the Jyuken Club, he was a delinquent, randomly picking fights with anyone.
- Souichiro initially looks like he's the hero of the story but towards the end Maya and Masataka take that role.