I only read up to about chapter 50 of the WN, which is just slightly ahead of where this is in the manga (yeah, let that be proof of how damned rushed and the pacing is too fast), but one thing that always bugged me was the Kazura's father not telling him anything about the other side or what he knew about it or anything. I mean, Kazura knows that his father knows about it and Kazura father knows he knows. So can we stop with this nonsense? We know time doesn't flow significantly different due to the trips Kazura has been making and we have little evidence to show that anyone since that long-dead corpse that Kazura found has travelled to the other side. Meaning that if Kazura's father DID go to the other side, he was VERY incognito and low key or didn't do much.