|Occupation||Trainee Railway Security Force|
|Affiliation||Japanese National Railway|
|Novel||RAIL WARS! Light Novel Volume 1|
Naoto has short black hair that reaches down to his neck with black eyes. He usually wears a captain's hat, smart uniform, white gloves, and a band on his arm.
Naoto is a very gentle person, who is kind to everyone he meets. He is also very selfess, and will not hesitate to put himself in danger if he feels it is a necessary course of action. However, his gentle personality does not preclude him from staring at Haruka Kōmi's body on rare occasions.
He is very knowledgeable in train types and models and has extremely passionate about them.
Naoto was first inspired to work on the Japanese National Railways system when he was a young boy. At the time when he was little, he fainted in the snow because he was very hungry, a train that was passing by picked him up and took him to the nearest hospital. The man who saved him became his inspiration to becoming a train driver. He then developed his passion for the railway and trains.
When the two first meet, Haruka became embarrassed when Naoto looked at her pants. He befriended her when they both started their railways classes; she was the first person he befriended. Even though there have been embarrassing moments, Haruka would always be kind to Naoto. Over the course of the series, she appears to develop romantic feelings for Naoto and even becomes jealous when other girls have his attention. It is later revealed that Koumi's feelings may have developed when Naoto saved her when they were children.
She is the first person that Naoto meets. Aoi jumped on his back and onto the tree to get a balloon for a child. At the beginning of the series, she is seen to be quite cold towards him, thinking that he's a pervert for staring at Haruka's body. Later on in the story, Aoi begins to understand and respect Naoto more; it appears she then started to develop feelings for him. They form a trust for each other later in the series. Sakurai, like Haruka, is seen to get jealous when Naoto is in the company of other girls. She has a strong desire to protect him and tells him that when he becomes a train driver she will protect him and the train he is driving.
Naoto's first male friend who is the best in sports out of them two, he is extremely passionate and athletic. Naoto sat next to him in railway classes. Although their relationship isn't always shown in the anime, it is clear they both have great respect for each other. Iwaizumi tends to call Naoto, "Deputy Leader" and usually asks for permission to carry out an action during important missions.
Iida is the leader of Naoto's squad. She has great trust in Naoto and respects him as a person. Naoto often confides in Iida when faced with a difficult problem or he feels he is unable to do something, to which she expresses her trust in him; this is shown on many occasions: for example when Koumi was kidnapped, Naoto confided in Iida to which she told him he would make the right decision like he always does. Iida has also told Takayama often that she will cover for him or take responsibility for any decision he makes because she believes and trusts in him.
And old friend of Naoto's from school they met again while working for National Railways. Mari appears to have feelings for him.