Narumi Kanai is a literature teacher at a high school and the homeroom teacher for his class. He has known the student Hanabi Yasuraoka since she was a small child and has always cared for her, though he views her affection as that for a younger sister rather than romantically. He is tall, standing at 178 centimeters, with black hair and brown eyes, and has a gentle, calm, and approachable demeanor that makes others feel at ease. His personality is defined by kindness and a tendency to be oblivious to the romantic feelings directed at him, including those from Hanabi. His primary romantic interest is Akane Minagawa, a fellow teacher at the same school, and he harbors a quiet, somewhat shy crush on her. He tends to be attracted to women with long hair, a trait that ties into his feelings for Akane. His motivations center on his love for Akane and his desire to care for those around him, yet his lack of awareness contributes to the cycle of unrequited love at the heart of the story. Throughout the narrative, he remains largely unaware of the emotional turmoil he causes others, particularly Hanabi, and his development involves eventually marrying Akane and becoming a father. In terms of notable abilities, he is a dedicated teacher who takes his role seriously and is able to connect with his students, though he struggles with recognizing the depth of the relationships around him.