Kōta Oyamada is the central protagonist of Kanokon: The Girl Who Cried Fox. He begins the story as a first-year student who moves from a rural area to the city to attend Kunpō High School, having previously lived with his grandfather. On his very first day of school, he is called to the music room by the beautiful second-year student Chizuru Minamoto, who confesses her love for him and accidentally reveals that she is a fox spirit, or kitsune, over four hundred years old. This encounter plunges Kōta into a world of supernatural romance and daily chaos.

Kōta is portrayed as a gentle, timid, and indecisive young man. He is extremely innocent and easily flustered, especially by Chizuru’s persistent and overtly physical advances. Despite his initial reluctance and attempts to maintain a proper relationship, he gradually becomes more accustomed to the extraordinary situations around him. His personality is mild-mannered, and he often finds himself caught between the affections of Chizuru and another supernatural being, the wolf spirit Nozomu Ezomori, who transfers into his school and class. Kōta’s motivations center on navigating these intense romantic entanglements while trying to live a normal high school life, though he genuinely develops strong feelings for both Chizuru and Nozomu over time.

His role in the story is that of the human catalyst who triggers conflicts and emotional growth among the various yōkai characters. He is often the target of jealousy and competition, particularly between Chizuru and Nozomu, but his earnest nature earns him allies and protectors. Key relationships include his bond with Chizuru, who becomes his fiancé-like partner; his growing connection with Nozomu, who openly pursues him; his friendship with Chizuru’s adoptive younger brother, Tayura Minamoto; and his interactions with classmates such as the rule-strict class representative Akane Asahina, who disapproves of his relationships. Kōta also develops a reputation around school for the increasingly eccentric and intimate activities he engages in with Chizuru, earning him nicknames among his peers.

In terms of development, Kōta evolves from a shy, overwhelmed country boy into someone more confident and accepting of his extraordinary circumstances. He learns to express his feelings, eventually declaring his love for Chizuru, and becomes more proactive in protecting those he cares about. Though he remains largely a normal human with no supernatural powers, his presence is significant to the spirits around him. A notable personal detail is that he cannot swim due to a childhood trauma from nearly drowning. As the series progresses, Kōta advances to his second year of high school and continues to grow into his role at the center of a supernatural love polygon, all while retaining his core gentleness and sincerity.