I was quite worried about the ecchi tag on a seinen, but luckily it's really toned down. Too many good stories get lot in all the fanservice after all.
Really appreciated all the Lovecraftian references, the author even go with the "Shub-Niggurath is a fertility deity" theory, so they have at least a decent grasp on the whole mythos.
Still not sure what the dog girl is supposed to be, but going by the "mass of spheres" thing she looks to be Yog-Sothoth's spawn? There was a bunch of dog people worshipping him in some story IIRC.