>>150002296
It's implied that Yuu is already partially insane, so seeing his "big sister's" breasts shouldn't cause him to lose any Sanity.
I assume that the Dating Books are supposed to be a spoof on the Necronomicon?
Also, is everyone considered an "Outer God"? IIRC, only Azathoth, Yog-Sothoth, Nyarlathotep, and sometimes Shub-Niggurath were at that tier.