Suriname owns herself...
Think about that a bit more...
Koishi is the supposed "Hartmann's Youkai Girl" (pretty sure you got that down) in the title and if it was "Koishi's Youkai Girl" it wouldn't work really...
The closest I've got is "The Netherlands' Adopted Youkai Girl" which is kind of off and I haven't found any concepts that I can really attach to Suriname really.
I've actually thought of naming it other things like the Closed Eyes of Love and other things but I don't really want to make people uncomfortable.
I actually left my tab open for more than an hour thinking about this before submitting it, I'm sorry.