The Devil is a Part-Time light novel author Satoshi Wagahara revealed the real-life locations that he visited on research trips for his stories in the March 2019 issue of Dengeki Bunko magazine. The report is the first in what the magazine promises to be a regular feature focusing on the research light novel authors perform for their stories.

Wagahara wrote that his first real research trip was for volume 4 of The Devil is a Part-Timer! . The setting of the story shifts from Sasazuka in Tokyo to Cape Inubō in the Chiba prefecture. Wagahara recalled that he took this trip in September 2011, and so traces of the Tōhoku earthquake were still faintly in the air. The experience had a strong impression on him, and he ended up including a lot of references to the locale in the volume that wouldn't be evident to the reader unless they had been there themselves.

Wagahara appears to focus heavily on transport in his research. Volume 7 takes the characters to the Seiseki-Sakuragaoka station, which is accessed by the Keio line from Sasazuka station. The traffic conditions described in volume 11 are also based on the experience Wagahara had while researching bus routes from Chō fu. The traffic was so bad that the bus was at a standstill for 10 minutes. His observations were incorporated into the novel.

Wagahara's latest novel series The Hero's Son (Yūsha no Segare) also incorporate research from a real-life locale. The protagonist attends a prep school called "Chiaki Institute," which is based on an unnamed real-life prep school. Wagahara went to the location and conducted interviews with the teachers. The assistant teacher Yusuke Kobayashi is based on the anecdotes he heard and the things he observed from watching classes in action. Although the character does not actually do much in the story, his presence adds to the sense of reality in the series.

Even stories that aren't set in the real world at all require research, Wagahara noted. For his novelization of Star Ocean: Anamnesis, he was sent plenty of materials, but he felt it was necessary to replay the game itself to get a sense of its world and characters.

For his newest yet-to-be-announced work, Wagahara went to the Okayama Prefecture for research. He wrote that the reason he went to Okayama was to study Japanese swords. However, he gave no further details about what kind of story his next work will be.

Wagahara's debut novel The Devil is a Part-Timer! launched with 029 's illustrations in 2011. It inspired a television anime in 2013. The Hero's Son first launched in 2017. The 3rd volume was released on July 2018.