'Hiroshi Kuzumi (九澄博士) is the main character of Okami Kakushi. He is a 15 year old boy who moves to the city of Joga with his father and his younger sister, Mana. Many people usually call him "Hiro" or "Hakase", which means professor. He is voiced by Yū Kobayashi in the anime.
In the anime, he first moves to a city called Jouga.
After he moves to his new home, he meets Isuzu; who falls in love with him and latches onto him.
The next day, he goes to school and is greeted by all of his classmates, except for Nemuru, who tells him that his existence is very annoying. After school, Hiroshi's two best friends, Isuzu and Kaname, gives him a tour of the city and tells him about the hassaku oranges and the festival that is about to happen.
The next day, one of the students that greeted him was absent. Nemuru tells him that he transferred. As the story progresses on, he learns that more and more people died; including Isuzu's older brother, Issei. He meets more residents including a lady named, Kaori, and Sakaki, a man who is searching for something.
One night, he observes a Fallen being slain by a group of murderers and tells Sakaki, a man he met at Kaori's house about it. After Issei's death, Isuzu begins to skip school. Hiroshi is bothered by this and tries to talk to her, only to be turned away by Isuzu's mother.
Isuzu calls Hiroshi that night and asks him to meet her at a park. He goes, only to be attacked by a Fallen Isuzu. The group of murderers appear and Nemuru is revealed to be one of them. Isuzu fights Nemuru, only to be defeated by her and brings Hiroshi to an unknown area.
She confesses her love to him and tells him that she doesn't wish to be killed by Nemuru and jumps off the building. She is then caught by the masked murderers and Hiroshi tries to follow them but is stopped by Nemuru. He asks what is going on but she knocks him out wih her scythe. He wakes up in his bedroom the next day and realizes that both Isuzu and Nemuru are absent from school.
Kaname tells Hiroshi about her theory about the Jouga wolves. At night, Sakaki contacts Hiroshi and tells him to meet at an abandonned shrine. Sakaki tricks him and locks him in the shrine with a bound Nemuru. Hiroshi asks Nemuru about Jouga's secrets and she tells him everything he needs to know. He frees her, but Nemuru was on the verge of becoming a Fallen.
She manages to stop herself and both their fathers frees them. After all those events, the Hassaku Festival occurs. Hiroshi and Kaname goes to the festival but is ruined but the arrival of the girl Issei kissed. She is later killed by Nemuru and her acolytes. Sakaki arrives and exposes the secret of the Jooga wolves to the crowd.
The wolves turn on him and Kaname but Nemuru and Isuzu intervane. A man from the Vigilance Commitee member tells the whole crowd about Sakaki's plan to drown the whole city in water. Hiroshi, Kaname, Isuzu, Nemuru, and her acolytes rush up the stairway to get to the dam controls.
Hiroshi and Kaname continues to go up the stairs while Isuzu, Nemuru, and her acolytes take a shortcut to the controls. After Nemuru's group disables the controls, Isuzu follows a trail of blood created by an injured Sakaki, but only to get shot on the knee by him. The whole group arrives and Sakaki threatens to shoot Isuzu. Hiroshi tries to protect everyone but is beaten and push aside by Sakaki.
Nemuru, then offers herself to get shot on a deal that Sakaki will not kill everyone. Before he could do anything, Kaori and the other priestesses arrive to stop him. Kaori tells Sakaki to shoot her if he wants to destroy the city. Sakaki attempts to shoot Nemuru instead but Kaori takes the shot. She drags him down the river below and dies with him. After those events, Hiroshi concludes that the city is peaceful again, but not for long as he knows that the people who left the city will tell everyone about Jouga.
Upon Isuzu and Kaname rapidly telling Hiroshi to call Nemuru by her first name, not by her last name, he says it for the very first time and Nemuru becomes best friends with them. Six months after the Hassaku Festival, Hiroshi, Nemuru, Kaname, and Isuzu meet at the Jouga ice-cream parlour and talks about some events in the past such as Nemuru visiting Hiroshi's house dressed in a Uraesu costume and Hiroshi being invited to a cafe and forced to dress as a maid for an interview. Hiroshi then remembers his encounters with Nemuru and Isuzu and how they changed throughout the story.
Hiroshi has black hair, has a pair of square glasses, and his eye colour is purple. He is seen as a very timid character.
He usually wears his school uniform which consists of a white T-shirt and pants and brown shoes.
Hiroshi and Mana are very close siblings. Mana is usually annoyed by Hiroshi always helping her get down small steps.
Hiroshi and Isuzu are close friends. Isuzu is in love with Hiroshi and is always with him when they are on their way to school.
Hiroshi and Kaname are close friends. She helps him know more about the city and talks to him a lot about the legend. Kaname likes to talk to Hiroshi's dad about the legend of the Joga wolves and visits his house often to give Hiroshi's dad her notes.
Hiroshi and Nemuru's relationship took off with a rocky start. At the beginning of the series, she thinks his existance is annoying. Later on, it is revealed that she was trying to protect him by killing all of the humans that are addicted to Hiroshi's scent. When Hiroshi and Nemuru are trapped in a warehouse, she attacks Hiroshi but is able to stop herself from kissing him. At the end of the series, Hiroshi says Nemuru's first name for the first time and Nemuru joins Hiroshi's group of friends.