Kurei-san is SF

This chapter is a delightfully weird tale, which involves a female
alien who has come to Earth to conduct occult research. That's
a fascinating cross-genre premise I've never seen before (which
is really saying something, because I've read a lot of weird tales).
I hope Hiyoshi Hana is planning some sequels, because it would
be a waste to limit such a great concept to a single chapter.

Kurei's fashion ensemble is excellent, with a trim waistcoat and
a ruffled jabot (which is pinned with what I assume to be a large
occult gemstone). Her lab coat has overlong sleeves, which she
never bothers to roll up. That's a cute, funny touch.

As for her physical appearance, those wonderful,
alluringly sleepy eyes are simply irresistible.

I love the way Kurei analyzes her sensations while she's being
fucked for the first time. What begins (for her) as an objective
experiment quickly becomes a pleasant subjective experience.
(page 10, panel 3)

That's a brilliant cross-genre premise I've
never seen before. I wish I'd thought of it.

It could also be a human-female clone. If their technology is advanced enough in the setting, it's possible that they can essentially download and upload data from organic lifeforms. This would allow for a copy of the memories and personality of one of the aliens to be installed in the body, and to get the language data, they'd simply have to- shall we say 'acquire' it- from one of the natives, sorting out only the necessary information to prevent potential complications. It isn't too farfetched either, when you consider that DNA could be considered a series of codes for organic tissues to follow to produce an organism and I believe there is some research being conducted into storing data in living cells. It was mentioned in an article in IEEE Spectrum several years ago, if I remember correctly.

Of course, that begs the question as to why an alien with access to such technology would be interested in the occult, but it's possible that, from their perspective, such a strange thing may indeed be worth investigating.

"I can't wait to find out what your sperm will allow me to give birth to."
(page 9)

Either Kurei wants to conceive a human/alien hybrid (and she's using
the word "homunculus" instead of "baby"), or (more likely) she wants
to create a true homunculus with traditional occult methods, possibly
by using her own womb as an alchemical "oven."
https://en.wikipedia.org/wiki/Homunculus

I'd like to see Kurei's laboratory, which probably contains
an eccentric collection of modern equipment, alchemical
paraphernalia, and strange occult artifacts.

I like the way Kurei playfully refers to the MC as "Earthling"
(which suggests she's probably familiar with Earth's corny
sci-fi pop culture).
(page 20, panel 5)