Girls are invaded by parasites to form a symbiotic codependency.

Each girl is violated by some orifice, and then the parasites couple with their systems.
The premise is a bit squirmish, if you like tentacles x girls this is recommended.

9 base CGs, text and text-free sets, many variations for about 200 total works.

DLsite: http://www.dlsite.com/ecchi-eng/work/=/product_id/RE149832.html

pixiv: https://www.pixiv.net/member.php?id=636935

This artist really doesn't know where anuses are positioned

Base +6, Bluelight0037 +12, fallensand +6