Doing searches on "dainihon samurai girl" doesn't yield anything but this Doujin. Is this based off any anime series, and if so what is its name?

I only ask because there doesn't seem to be a lot of samurai action in this... at least not with the steel variety of sword, which makes me think there's an underlying story.

Base +10, ifuko +6

It's a light novel which deals with politics/economy apparently. According to a google transate.

I'd post the wiki link, but all the characters turn into a mess of numbers, copy/pasting the japanese title at the end of the doujin name in google will get you there.

Base +7

"Shut up and take my virginity"

Base +11, tedderböse +6

https://www.doujinshi.org/book/556694/Himari-Manifesto/

Base +47, hondawhr -24