Live action TV
Description
Gessai Obata is the master who raises and trains the young assassins at the center of the story Azumi. His name is presented as Gensai Obata in the original source material, while the live-action film adaptations refer to him as Gessai. He is an older, skilled swordsman who operates in the aftermath of Japan's Sengoku civil war period.

Gessai Obata is a pragmatist whose personality is defined by a chilling single-mindedness. He believes that the only way to achieve a greater political goal, namely peace and unification under the Tokugawa shogunate, is through the cold-blooded elimination of its enemies. To this end, he has dedicated his life to creating the perfect, unfeeling assassins, a process that requires the complete destruction of normal human emotions and attachments in his students. His methods are brutal and leave no room for weakness or hesitation.

His primary motivation is political: to prevent a return to widespread civil war by assassinating the warlords and prominent supporters of the Toyotomi clan who threaten the uneasy peace. He operates with the apparent sanction of the Tokugawa regime, believing that the murders he orchestrates will ultimately save more lives than they take by averting a larger conflict. This utilitarian logic drives every one of his actions.

In the story, Gessai Obata serves as the harsh catalyst and guiding hand behind the protagonist, Azumi. He is not a field agent but the architect of the entire assassination plot. He selects orphans, secludes them in a hidden valley called Kiridani, and trains them from childhood in swordsmanship and ninjutsu, isolated from normal societal concepts like family or marriage. His most significant role is his final test for the ten students: after having them pair up with their closest friend, he coldly commands them to slay their partner. This act is designed to sever their last human bonds and transform them into living weapons capable of murder without question. After this culling, he leads the five survivors, including Azumi, on their missions to eliminate the designated targets.

His key relationship is, of course, with Azumi, his most gifted student. He is both her surrogate father figure and the source of her deepest trauma, having forced her to kill her best friend, Nachi. He constantly tests her resolve and attempts to suppress her burgeoning doubts and compassion, teaching her that sentiment is a fatal flaw in an assassin. He also trains the other children, all of whom he sees as disposable tools for the mission.

The character of Gessai Obata shows little internal development; he remains steadfast in his brutal ideology from beginning to end. His role is to be the unchanging pillar of a ruthless philosophy. The development is seen in the results of his training, as Azumi and the others struggle with the legacy he has forced upon them, often questioning the morality of the killings he has ordained. His methods create the central emotional and philosophical conflicts of the narrative.

Notable abilities include his mastery of swordsmanship and combat tactics, which he uses to instruct his students from a very young age. More prominently, his abilities lie not in physical combat but in psychological manipulation and strategic planning. He possesses the foresight to train a team of assassins for a long-term political goal and the ruthlessness to execute his training program, including the order for his students to murder one another, without any visible hesitation or remorse. His greatest skill is in creating effective killers.