Satoru Nishimura is a first-year high school student and classmate of Takashi Natsume in Class 2. He has short brown hair, brown eyes, and stands slightly shorter than Natsume, Atsushi Kitamoto, and Kaname Tanuma. He wears the standard school uniform of a white collared shirt and grey pants. Nishimura is funny and easy-going with a slightly perverted sense of humor. He and Kitamoto actively befriended the initially reserved Natsume when he transferred; Nishimura was the first to speak to Natsume in class, an act Natsume later remembered fondly. Their friendship grew through shared activities like Nishimura teaching Natsume to ride a bicycle. He shares a close childhood bond with Kitamoto, though they are in different classes. Nishimura nurses an unrequited crush on classmate Tooru Taki, often asking Natsume to help invite her to group outings. At home, he frequently argues with his mother over minor issues like lunch and has an older brother who briefly helped fold paper cranes, prompting Natsume to reflect on his lack of siblings. Nishimura once became possessed by an unseen spirit, causing heaviness on his shoulders and heart. Under its influence, he lashed out at Natsume over paper cranes and fled into a forest. Semi-conscious during the exorcism by Madara and Natsume, he overheard Natsume express gratitude for their friendship. This experience strengthened his protective instincts toward Natsume, though he remained unaware of the supernatural causes. He consistently shows concern for Natsume's well-being. When Natsume blamed anemia for a spirit incident, Nishimura researched the condition and brought him iron-rich curry bread, insisting on walking him home. He expressed frustration when Natsume sought help from Tanuma instead of him, teasing about their closeness while reaffirming his own willingness to help. His persistent efforts to include Natsume in activities like bike rides and group gatherings played a key role in helping Natsume gradually open up to human connections.