[He frowns a little, did that bitch tell other people this!!]

Right. Some of the people in Amatsuki have real bodies in Higan, but some people are only a part of the "fake" world in Amatsuki.
[Himself included.]

For all we know, this place could be like Amatsuki in that way. It would explain a lot, like how I'm here. If someone found that out...
[Well, what's the big deal killing somone who's just an NPC?]