A very old post, published at least several years ago. It had probably been casually posted somewhere like 2ch, along with a photograph.
The gist was that while taking a train back into Tokyo at night, the poster had accidentally caught sight of a mountain-sized black silhouette on tracks near the wilderness, roaring violently amidst the hills.
The train had sped past too quickly for him to react. He had only managed to snap a photo with his phone.
Unfortunately, due to the high-speed motion and the train window between them, the picture was covered in heavy moiré patterns. The phone was probably some cheap model too. It was basically just a patch of black, with almost nothing visible.
After zooming the original image to the maximum and studying it for a long while, they could barely make out the circled "ape-like shape" in the darkness. In this still photograph, rather than resembling an upright humanoid with four limbs, it looked more like a strange rock captured from an accidental angle.
Yet this was already one of the few clues from the vast sea of data that could barely be considered relevant.
After confirming that the other information was even less reliable, the middle-aged man beside them followed instructions and conducted an in-depth trace of the post. Once he confirmed the poster's forum details and the actual IP addresses from his posting history, he rapidly sorted and compiled the data into a red-dot distribution map. "Right here. Assuming there haven't been any major changes recently, judging from the historical logins and access records, this person's main area of activity should be within this range."
This middle-aged man was clearly quite skilled.
After circling a small area on the map and sending the information chart to Li Ce, this "cheap brother-in-law"