Sōjirō Agata served as the president of Kaimei High School’s Student Council during his third year, where he gained a reputation for his intelligence, composure, and ability to maintain balance within the student body. Under his leadership, the council functioned with a sense of stability and mutual respect, with Sōjirō often acting as both strategist and mediator during disputes between clubs and students. His guidance helped establish a cooperative relationship between the Student Council and the Sket Dan, even when tensions arose between the two groups.

After stepping down from his position near the end of his final year, Sōjirō chose Sasuke Tsubaki as his successor, recognizing his potential for leadership despite their contrasting personalities. His influence continued to shape the council even after his graduation, as many members, including Tsubaki and Kikuno Asahina, retained deep respect for him.

Outside of his role as president, Sōjirō is also known for his strong familial bond with his younger sister, Saaya Agata, toward whom he shows a combination of affection and overprotectiveness. His actions toward her, though often exaggerated, highlight the more emotional and human side of his otherwise composed nature.

Sōjirō Agata is depicted as a tall, well-built young man with an athletic physique. He has dark, slightly messy hair that falls loosely across his forehead in a style resembling a faux-hawk. His composed yet easygoing expression is complemented by a characteristic, charming smile that reflects his laid-back attitude. Within the series, Sōjirō is noted for his good looks briefly acknowledged by Himeko and openly admired by Yabasawa making him one of the more striking figures among the Kaimei High School Student Council members.

Sōjirō Agata is portrayed as an easygoing and seemingly lazy individual, though beneath his relaxed exterior lies a sharp and calculating intellect. With an IQ of 160, he demonstrates exceptional analytical ability, often outsmarting others in complex situations or solving intricate puzzles with ease. His shrewdness is revealed in moments where he subtly manipulates circumstances for his own amusement or to influence others, such as encouraging Bossun to wager the fate of his club during the Gachinko Vivage Battle, or orchestrating situations to force Sasuke Tsubaki and Bossun to spend time together.

Despite his cunning, Sōjirō maintains a charismatic and approachable demeanor, which earns him the respect and loyalty of his peers, including Tsubaki and Kikuno Asahina. His leadership as Student Council President is marked by strategic thinking, calm judgment, and an ability to mediate conflicts effectively. However, his rationality falters when matters concern his younger sister, Saaya Agata. His protective instincts toward her frequently lead to overbearing or meddlesome behavior, particularly when it involves her romantic life, often resulting in comedic or disastrous outcomes.

Sōjirō Agata is portrayed as exceptionally intelligent, possessing an IQ of 160. His analytical and deductive reasoning skills allow him to solve complex problems with ease, often outpacing his peers. This intellect is prominently demonstrated during the Enigman Challenge, where he successfully answers all of Enigman’s riddles using only the incorrectly answered cards submitted by his Student Council members.

Another display of his intellect occurs when he is forced to solve a series of riddles devised by Sasuke Tsubaki, Bossun, and the rest of the Student Council during a mock kidnapping of his sister, Saaya. Despite the elaborate setup, Sōjirō is able to piece together the clues and resolve the challenge efficiently, further emphasizing his logical thinking and composure under pressure.

Saaya Agata
Sōjirō Agata has a strong protective attachment to his younger sister, Saaya Agata, often referred to as a “sister complex” by other characters. Normally calm and composed, Sōjirō loses his rationality whenever Saaya’s well-being or personal life is involved. He becomes easily flustered or overreactive when she expresses interest in someone or finds herself in potential danger, such as during her mock kidnapping incident. Despite his overprotective tendencies, Sōjirō’s behavior stems from genuine concern and affection, highlighting a softer, more emotional side beneath his otherwise strategic and unflappable personality.