Kotaro Higuchi is the main character of the anime Pita-Ten. He is a sixth-grade student at Misaki Seiei Private Academy. His early childhood was marked by tragedy when his mother was killed while saving him from a speeding truck. Since his father is almost always away working, Kotaro is left to take care of himself and his household, which has forced him to grow up quickly. This solitude, combined with the trauma of his mother's death, has shaped his personality into that of a quiet, reserved, and stoic boy. He is highly mature and responsible for his age, but this maturity hides a deep sense of sadness and loneliness. Kotaro struggles under the pressure of his middle school entrance examinations and is prone to keeping his thoughts and feelings locked away from others.

Kotaro possesses the unusual ability to see angels, demons, and spirits. This ability, which he ironically dislikes, makes him a unique bridge between the ordinary and supernatural worlds. His quiet, lonely life is completely disrupted when the hyperactive apprentice angel Misha moves into the apartment next door. Misha is relentlessly cheerful and clings to Kotaro despite his initial resistance. Through her constant, well-meaning interference, she gradually chips away at his emotional walls, helping him to open up and experience genuine happiness. An important part of Kotaro's story is his growing romantic feelings for Misha, which form the central emotional arc of the series.

Kotaro's life is further complicated by the demon Shia, who also becomes his neighbor. In the anime, Shia has no blood relation to his family, and Kotaro is initially drawn to her quiet and gentle nature. This creates a love triangle that puts a strain on his friendships. Despite these supernatural entanglements, Kotaro maintains strong bonds with his school friends, Koboshi Uematsu and Takashi Ayanokoji. Koboshi harbors a crush on him, while Takashi acts as a calm and reliable best friend. Kotaro is the emotional anchor and focal point of the story, often reacting with exasperation to the chaos around him, yet his personal growth is the heart of the narrative. Over the course of the series, he develops from a deeply wounded and isolated boy into a much happier and more emotionally open young person, learning to face his problems and find joy in his relationships. Aside from his perception of the supernatural, Kotaro has no other special abilities; his strength lies in his resilience and his capacity to learn to trust and love again.