TV-Series
Description
Yūji Sakamoto acts as class representative for Class 2-F at Fumizuki Academy, an institution that sorts students by academic performance. Though highly intelligent and a former child prodigy in elementary school, he intentionally neglected studying for the placement exam, landing himself in the lowest-ranked class. This deliberate choice reflects his firm conviction that academic grades do not determine a person's worth.

Academically, his strengths focus on history and strategic planning, though initial test scores suffered due to lack of effort. A pivotal loss to childhood friend Shōko Kirishima on an elementary school history test ignited his motivation, leading to rapid grade improvement over subsequent months. This academic surge directly strengthened his summoned being. He obtained a platinum bracelet following a tournament, which grants him the ability to deploy a summoning field at the cost of points and temporary loss of summoning capabilities.

During summoner test wars, he serves as Class F's primary tactician, crafting intricate strategies that utilize psychological warfare and leverage his classmates' unique abilities. His plans often manipulate rival classes into conflicts to weaken them before direct confrontation. While effective, opponents frequently perceive these tactics as underhanded or cowardly. His summoned being typically manifests equipped with brass knuckles and clad in a punk-style long coat with white pants. For occult-themed events, it transforms into a werewolf embodying wildness. Experimental summoning tests have yielded variants, such as an embarrassed masochist adult version he immediately dismissed.

Personality-wise, he projects a laid-back demeanor yet exhibits fierce competitiveness when challenged. He displays sadistic tendencies through frequent bullying of best friend Akihisa Yoshii, counterbalanced by genuine compassion—defending Shōko's feelings or protecting Akihisa from bullies during the cultural festival. He harbors a strong fear of Shōko's aggressive romantic advances, though his summoned being has inadvertently exposed his concealed affection for her. This contradiction extends to his moral flexibility: employing ruthless tactics in test wars while maintaining steadfast loyalty to friends and class.

His background features a longstanding academic rivalry with Shōko Kirishima dating back to elementary school, where both were recognized standouts. Their dynamic evolved into mutual romantic tension, with Shōko actively pursuing marriage while he resists her advances. An OVA storyline reveals that failing to maintain academic performance would result in immediate marriage to Shōko. His family includes his mother, Yukino Sakamoto; his father remains unmentioned.

Throughout the series, his character evolves from a reluctant Class F strategist to a more responsible leader. By the light novels' conclusion (Volume 12.5), he advances to Class 3-A and assumes the role of Disciplinary Council President, with Toshimitsu Kubo as vice president. His tactical prowess peaks in Volume 10, where he nearly secures victory against Class A before external interference forces a draw.