DLSite-
https://www.dlsite.com/maniax/work/=/product_id/RJ01648825

Raw-
https://e-hentai.org/g/4001717/75e5996ca7/

On pages 36, 37 and 60 the succubus just straight up has a smartphone. Well, that's... something, I guess?
At this point, I guess the only thing I'm surprised about is that this wasn't one of those "smartphone app instant hypno" doujins.

Base +6, bjacob98 +6, The14thNoah +13, sepso +6, Radvaldur +6

>medieval fantasy
>smartphone out of nowhere
uhuh...

Base +8, pooppandapoo +6, The14thNoah +13, sepso +6, qawzsexdrcft +6, Nonamewalker +6, Radvaldur +6, as102 +15, Bakster123 +8, Ice_cream1 +6, Fag153151 +6, Passtin +6

Maybe she took it off an isekai smartphone adventurer

Base +6, pooppandapoo +6, Cigarilo +8, The14thNoah +13, alphabetagama +8, sepso +6, 151132 +8, TheGreatestCool +6, as102 +15, BaggyLastard +9, Slayer Liberator +8, Fag153151 +6

I mean you also got vibrators, bondage equipment, milkers etc etc

Base +6, Cigarilo +8, The14thNoah +13, sepso +6, venfare +11, q0w9e8r7 +6, 151132 +8, as102 +15

I think everyone's ignoring the obvious answer: It's actually contemporary/urban fantasy, and this is just an old town that hasn't modernized much since good construction means older buildings are still largely intact.
Alternatively it's the gag where the netherworld is shockingly modern.

Base +6, Cigarilo +8, The14thNoah +13, sepso +6, venfare +11, 151132 +8, fapping_all_night +6, Absent Bishop +6, as102 +15, Slayer Liberator +8, Fag153151 +6

Succubi apparently are 21st century. While humans are like 16th century

Base +12