Seigi Akoku

Seigi Akoku (セイギ) is a highschooler attending Fourth East High School and a member of the Devil Hunter Club.

Appearance
Seigi is a heavyset teenager and is taller than average. He wears the typical male uniform of a high school student and a black military cap. When fighting Yuko, he wore spiked brass knuckles. After his battle, he lost an eye, which is bandaged and later replaced with a black eyepatch.

Personality
He seems to be steadfast and disciplinary, going right into the action when Yuko attacked the school to buy time for more Devil Hunters to show up.

Justice Devil arc
When Yuko attacked Fourth East High School, he and two other members of the Devil Hunter Club attacked Yuko. Though he was able to successfully injure her with his brass knuckles, he was taken down and his right eye was wounded.

Dating Denji arc
In the aftermath of Yuko's attack, Akoku reports to the club and student council president, Haruka Iseumi, about Asa's performance against Yuko. Outside the school, the remaining members of the Devil Hunter Club approach Asa and formally welcome her to their group.

The Devil Hunter Club, with Hirofumi Yoshida tagging along, go to Tanashi Aquarium, where they encounter Asa Mitaka and Denji, who were having a date there. As the group realizes they have been trapped inside the endless hallway of the aquarium, Seigi points out that it is the work of a Devil, who they must kill to free themselves. Because the Devil cannot be found, the group search for other ways out, to no avail, then convenes inside a lounge room, where Seigi and Yoshida bring fish for them to cook and eat.

Asa reveals her cell phone, which excites Seigi and the others as they now have a chance to get a signal to call for help. However, Asa falls over and breaks the phone, shocking and disappointing her classmates. With no options appearing before them, the students begin to give up, and Seigi tries to bide time by practicing his punches. Suddenly, the group is freed from the aquarium, which Asa has transformed into a spear to fight the reincarnated Eternity Devil. Asa kills the Eternity Devil in one blow, astonishing the Devil Hunter Club. Afterward, when the Public Safety Devil Hunters arrive, the club members explain the situation.

Skillset

 * Hand-to-Hand Combat: Seigi excels in unarmed combat. He has displayed impressive skills, capable of blocking an attack from a transformed Yuko with quick reflexes, then landing multiple hits on her in succession.

Trivia

 * Seigi's surname is an archaic spelling of Argentina in Japanese.
 * Seigi shares a passing resemblance to Agni, the main character of Fire Punch, one of Tatsuki Fujimoto's previous manga series.