An investigator who works under Detective Gotou initially enjoys the supernatural but becomes fearful of it after experiencing it firsthand. Despite this, they remain fascinated by supernatural phenomena and sometimes attribute events to such causes. Although Gotou does not highly regard Ishii, Miyawaka and Yakumo think highly of him. Over time, Ishii develops greater confidence in their abilities and begins voicing dissenting opinions against Gotou. They admire and respect Gotou, aspiring to become a detective like them. Additionally, they have romantic feelings for Haruka.
In volume 5 of the light novel, Gotou got kidnapped. Ishii was able to eventually figure out the case and where Gotou was hidden and saved him. Although he was led into saving Gotou by the real culprit, it was the first time Ishii was on his own and was able to figure things out.
In the first volume more of Ishiis past was revealed. He didnt have much friends during school, he closed himself off from others. He wrote a manga an
In the first volume more of Ishii's past was revealed. He didn't have much friends during school, he closed himself off from others. He wrote a manga and had wanted to go professional one day but his father did not allow him and so Ishii ended up being a detective.He was bullied during high school by Kosaka Yukari and Mochizuki Toshiki. Ishii was called "glasses monkey" by them. Due to the bullying he came to hate them and the thought of wanting to kill them came into his mind often.
Because of this Ishii believed that he was the one who killed Kosaka Yukari (by pushing her down a shrine's stone steps), though of course it was later proven to be false.At the end of the volume it was revealed Toshiki had in fact wanted to be Ishii's friend at first. He approached Ishii asking about the manga Ishii wrote. However Ishii denied it and pushed him away. It was after that that Ishii was bullied.