Naoya Teshigawara

Naoya is usually superficial in nature. He is shown to have a sympathetic side, since he was the first one to talk to Kōichi Sakakibara, who was still not used to his surroundings. Naoya is very sociable, cheerful, energetic, and is a sports lover. He is a childhood friend of Tomohiko Kazami and a good friend of Yūya Mochizuki, and after Mei Misaki, he is probably Kōichi's closest friend, possibly followed by Yūya. Naoya is very loyal to his friends. He also seems to be (at least in his mind) a ladies' man, pairing himself with Izumi and Takako for the catching contest (which was his idea in the first place) when the group was at the beach. Naoya is also quick-thinking, immediately springing to the aid of both Junta and Yūya when they were in mortal danger. Academically, Naoya doesn't learn much at school, claiming that he doesn't know how he reached the 9th grade. He is optimistic and always careless and carefree. However, following Tomohiko Kazami's death, Naoya was riddled with guilt and became more serious and mature as a result. He is also very selfless and compassionate, regardless of his feelings for Izumi, as well as his fear of her during her run as head of countermeasures, he doesn't hesitate to tell her off when she accuses Mei Misaki of being responsible for the Class 3-3 deaths.

left|thumb|Naoya's appearance in the manga. Naoya is a young man with light brown hair (which is longer in the manga) and light brown eyes, and he shows a cheerful expression most of the time, yet can be serious if he needs to. He wears a blue sweater and a white T-shirt, unlike the others who wear their school's uniform. He usually wears a colorful shirt or a flowerish one (for summer) for his casual clothes, which Kōichi Sakakibara considered embarrassing. In "Hair Stand", when he, Kōichi, Reiko Mikami, Izumi Akazawa, Takako Sugiura, and Yūya Mochizuki were going to meet Katsumi Matsunaga, he wore a white and purple shirt and a yellow sun visor. In the live-action film, he has black eyes and hair.