Reading this long after the rest of y'all, and not going through your comments as I'm not finished with this volume yet.
So, Kazuhiro's gramps wasn't just make a chance comment that happened to line up with what was really going down.
Kazuhiro doesn't grasp that when he shifts worlds, he shifts worlds.
Who knows just how early on in his life it was when a near relative glanced in to see how he was doing in his sleep and saw the blankets slowly settle to the bed, the lump of his body no longer there.
If it's not a hereditary thing, I'm sure there was some freaking at first, but then when he reappeared in the morning, and the same happened night after night...
You adjust.
I suspect you would worry about what happens the first time he went to sleep in the arms of another, how they would react.
That no news of such freaking was heard could have one of several explanations, with variations, I suppose.
He never got close enough for such to occur, or he didn't do the world shift in such circumstances.
It didn't go poorly.
It did go poorly, but didn't cause a stir.
Options 2 & 3 have the sub-options of they travel with him or they don't travel with him.
Anyway, it'll be interesting to see what gets shared with him by his gramps down the line, now that his gramps knows that when he shifts worlds, anyone in his arms shifts as well.
Or at least a specific girl shifts as well, and she doesn't freak out about it.
Had to post, as this is where folks would get what I'm burbling about.
Ah!
I was nearly at the end!
Gramps could tell something was concealing the true form of her ears, and properly identified her as a half Elf half Fairy.
That, plus other comments of his, leads me to believe this inter-reality travel isn't new to Kazuhiro's generation of his family.
Ugh.
So, the one maybe-hero collects intriguing women, does he, and then discards them once bored.
And the rings on his hands are tied into this.
One wonders what race he really is...
Future volumes will hopefully reveal more, along with his getting his comeuppance, I hope.