TV-Series
Description
Kiyoshi Fujino is the central protagonist of the narrative and one of the first five male students to enroll at Hachimitsu Academy, a prestigious institution that is transitioning from an all-girls school to a coeducational one. He is a tall, handsome young man with a lean build, dark blue hair, and black eyes. His physique becomes noticeably more toned as a result of the physical labor and harsh conditions he endures during his incarceration in the school's Prison Block.

Kiyoshi stands out among his male peers as the most level-headed and rational member of the group. Under pressure, he displays strong resolve and is generally better at controlling his sexual desires than the other boys, who are often driven by their baser instincts. This composure is evident when he refuses to take advantage of his classmate Chiyo Kurihara during a moment of vulnerability. Despite this restraint, he is not without his own perverse tendencies and is capable of shocking his friends with actions like cross-dressing to escape prison. He can also be oblivious to his own selfishness, such as when he attempts to use money gathered from others for a personal purchase. While he serves as the sensible core of the group, his friends often note that he becomes noticeably shy, awkward, and flustered around Chiyo, a stark contrast to his more serious demeanor in prison.

Kiyoshi's primary motivation throughout the series is his deep and genuine love for Chiyo Kurihara, a fellow classmate. This affection is the driving force behind most of his major actions, including engineering elaborate prison breakouts, sacrificing his first kiss, and going to extreme lengths to nurture their relationship. His initial connection with Chiyo is built on a lie, as he feigns an interest in sumo wrestling, which she is a dedicated fan of, after she notices a sumo-themed eraser he owns. Despite this dishonest foundation, his determination to keep promises to her, such as attending a sumo match, demonstrates the sincerity of his feelings.

His role in the story is that of the main narrator in thought, providing the audience with a grounded perspective on the increasingly absurd events. He is frequently the one who engineers plans for the boys, whether it is to break out of the prison to keep a date or to help his friend Gakuto acquire a coveted collectible figurine. Although he is often at the center of the most sexually awkward and perverse situations, usually unintentionally, he remains the group's de facto leader and strategist.

Key relationships profoundly shape his journey. His bond with Chiyo is one of pure, idealistic romance, though it is constantly tested by his own lies and the chaotic circumstances he creates. His relationship with Hana Midorikawa, the secretary of the Underground Student Council, is far more complex and fraught with tension. It begins with an accidental, humiliating encounter where he witnesses her urinating. This incident sparks a twisted obsession in Hana, leading to a bizarre series of interactions where revenge, blackmail, and an uncomfortable intimacy become intertwined, eventually developing into a confusing mix of mutual antagonism and a strange bond. Kiyoshi also has a significant relationship with Mari Kurihara, Chiyo's older sister and the president of the Underground Student Council. What starts as a clear opposition between prisoner and warden evolves into an unusual rapport and a grudging alliance when they find themselves with a common enemy, leading to moments of mutual respect and awkward trust. His friendships with the other boys, including his middle school friend Shingo Wakamoto and the eccentric Gakuto, are also crucial. While these bonds are tested by betrayal and misunderstanding, they ultimately rekindle into a strong sense of teamwork as the boys work together to overturn their expulsion.

Throughout the narrative, Kiyoshi undergoes significant development. He begins as a relatively normal but frustrated teenager who lies to get closer to a girl. His experiences in the prison, from enduring physical abuse to engineering elaborate escapes, force him to grow. He learns to sacrifice his own dignity for the sake of others, as seen when he cross-dresses or subjects himself to public humiliation to help his allies. By the end of the major arcs, he has shown a willingness to confront his own actions and deceptions, even if his plans often end in spectacular failure. His resolve to make a proper confession to Chiyo, despite being ostracized for his actions during the Sports Festival, highlights his tenacity and emotional growth.

Notable abilities include his remarkable tenacity and his capacity to remain rational and devise plans under immense pressure. He is a skilled strategist, capable of thinking several steps ahead to orchestrate breakouts and counter the schemes of the student councils. Furthermore, he displays a high tolerance for physical and psychological punishment, enduring humiliations that would break others in order to achieve his goals of protecting his friends and winning Chiyo's affection.