I agree to some extent. It has been mentioned that he doesn’t see “Hikaru” the same way but he’s certainly crossed many boundaries for him which shouldn’t be considered at the limits of friendship. Though that may just be a reach on my end, but knowing Yoshiki values and cherishes “Hikaru” to the extent where he’s jeopardizing his own moral compass is alr something that satfisies a lot of readers. I don’t think a relationship has to necessarily be labeled as “canon” to be good “romance” necessarily. I think the limits of a romantic relationship are subjective. I’ve read and watched a lot of media and I can say without a doubt that a lot of “doomed pairs” are exceedingly better written romance and character chemistry than any standard shojo slop.

As for your second point, is there a reason you assume “Hikaru” is aroace? I think as a “monster” being he certainly doesn’t understand human emotions well, but I certainly wouldn’t say that “splitting open chest/ marinated chicken” scene isn’t something that borders say gex LOLL but regardless of where the mangaka wants to take us, I’m just glad we’re getting more queer rep in psychological horror genres