That's really interesting, because my read was like 180 degrees from that: This series has seemed to me not just socially conscious but about social consciousness so far, using fictional/mythical races as a way to safely talk about real-world issues in the way that sci-fi and fantasy often do.
I'm really not getting ecchi or fanservice from this as much as that it's supposed to be threatening (but not too scary.) Might accidentally hit for people who are, uh, into that sorta thing, but I'm not getting a vibe that it's intentional? The cliffhanger totally reads "they will be immediately interrupted next chapter or she'll reveal to him that she's only trying to make a point or something" but maybe it'll be subverted, who knows?
I can see this going all sorts of directions, including like you said, which is honestly rare. Maybe I'm giving it way too much credit.
Reading back over the first three chapters, I guess I can see where you're coming from, in terms of the content of their interactions and the language they use both internally with themselves and externally with one another/other people.
I think where I'm getting caught up is the succubus/supernatural entity element, surprisingly. But as you pointed out, sci-fi and fantasy are often used to create 'safe' lenses through which heavier topics can be explored, so Emu being a succubus here fits that bill if the author truly wants to push into that territory with these characters and their relationship.
I think the ecchi angle I'm seeing is also my expectation borne out by the fact that the female lead
is a succubus. That choice right there over something like a tengu or yuki-onna or straight up oni means there's bound to be a sexual component, and I would be
very surprised if that wasn't leaned into in the story in surface-level ways, as we can see by her friend pushing him down on the infirmary bed with intent to (by appearances) 'devour him'.
It could be this is all being set up for a big subversion that never crosses the line into lewd moments for the main pair, but it's a big hangup between them and their prospective relationship, so I'm hard-pressed to see how it won't become a factor. And we already have little bits and pieces to this point of him checking her out in this panel or that, even if it's "unintentionally", so there's definitely a fanservice element in how Emu is portrayed by the manga itself, even if (again) it's for deeper purposes related to her character and her actual narrative arc.
It's not just one thing all on its own for the sake of visual titillation, basically.
That all said - I too want to be a more optimistic person when it comes to new stories, so I really want to give this as much credit as you are. I also just tend to be very cynical a lot of the time due to .....
gestures broadly at everything so I could do to remember to be a bit more whimsical at times, I think.
