Katsumi Shibata (柴田 克己, Shibata Katsumi) was an old classmate of Natsume's in primary school. However, when he first appeared, Natsume did not remember who he was. Shibata is one of the few people who knows that Natsume can see youkai, although he did not believe him when were younger.
Shibata went to the same primary school as Natsume, and used to call him a liar and bully him for claiming that he could see youkai.
Years later, he first met Murasaki in a park. After that he started seeing her once in a while. They started talking and hanging out together. Gradually he fell in love with her, and figured that she felt the same way about him. However, he thought that something about her was weird, so he decided to ask Natsume to confirm if she was a human or not.
He went to search Natsume to ask for his help. He dragged Natsume while he was together with Nishimura and Kitamoto. Asking Natsume for money, he bought tickets for them to his town. There, he wanted Natsume to see whether Murasaki was human or a youkai. At first Natsume just laughed at him and said she was a human.
When Natsume met him the next day, he told Shibata that he was wrong and that Murasaki was actually a youkai. Angry, Shibata called Natsume a liar and left. That night Shibata went to the park to look for Murasaki, and realised that she was indeed not a human. After Murasaki faded away, Shibata apologised to Natsume and thanked him for passing on Murasaki's message. They made up their friendship after this.
- Main article: Takashi Natsume
- Main article: Murasaki
- Main article: Kaname Tanuma