I’m starting to pieces some of the things together.
That video had things related to the past Kinki stories. You can see the Mashiro-san apartment from chapter 3 and the Red Jacket Woman who raised her hands from chapter 6. The latter is particularly interesting. The 2 paranormal sensitive participants experienced something that suggest there was something jumping in the corner of the room and if you look at the red jacket women in both chapters, you can tell she’s also jumping up and down (you’ll have to focus on her feet in chapter 6).
Chapter 5 also mentioned a jumping woman, could this be the source? In that chapter, the MC actually suddenly looked at the corner too, just like the 2 paranormal sensitive participants.
This is actually super intriguing. It’s like a mystery told through horror stories.