@Bramia Oh but that's wrong, isekai is a sub-genre. It is one of those weird Japan semi-exclusive genres (another notable one is Slice of Life).
Heck even this site considers it a genre whereas thing like post-apocalyptic is considered a theme.
It's just a "thing that happened", and only happens once in almost every isekai series
By that virtue, romance is just a theme wherein there love just happens to occur.
Now 2 questions that potentially arise from this situation: First. If the likes of isekai and romance are genres (sub-genres or whatever) then what makes them different from themes like vampires or post-apocalypse?
Is it the approach? I mean you have a million ways that post-apocalypse has been rehashed whereas isekai has been so saturated that most of its tropes has been codified. But nah, that can't be right, this story itself is proof of that. It is isekai with barely any of the qualities.
Is it the pervasiveness? I mean isekai has saturated the industry so much that it became a sub-genre. Probably this, with the first point being a second consideration. I mean we have magical girl as a genre vs magic as a theme (oh the irony).
But now the 2nd question. If the genre isn't necessarily hinged on the tropes, apart from the most vital ones, then how the fuck can you say that calling this a great isekai weird?
Well quite simple actually: I'm not reading it for its isekai quality, nor does it add anything substantial. To say that it's a great isekai is to say that it uses the qualities of the genre to good use, which is, it barely uses it at all.