I see by the tags that the only thing I was fooled by for a moment, was the description's claim that I should not be fooled.
I am dubious about the claim to being "shoujo" here, web-comics being allowed to self-proclaim genre sometimes seems sketchy (though perhaps the person doing the tags based it on something else, I wouldn't know).
@meixiangsi:
Assuming you're not just trolling, then—whatever it may have to do with the morals or ethics of it—non-blood inter-familial, *ahem*, "relations" are indeed generally still considered to be incest by the public at large. Depending on your locality (and the precise relation), indeed, it may be felony. That is all in the real world, of course, not manga fetish land—but many of us (like myself) that don't want to read most incest manga are
still emphatically
not interested to read about (for instance) adoptive siblings going at it, either. And likewise for many of those who
do want to read read such things, I'd imagine.
TL;DR: The fact that readers are allowed to comfort themselves by saying "they're not blood related anyway", does not preclude it from being incest.