Inma no Seiiki ~Wasurerareta Mitsurin no Jiin Iseki ni Kodaibunmei no Chou Injuu o Mita!!~

Deep in the forgotten forest, verdant growth shrouded
the decrepit remains of a tribal temple... a dwelling of
dreadful violators!
Coiling tentacles constrict heroines in an orgy of hellish ecstasy.
A grand journey & tentacle assault AVG!

The archaologist "Prof" (main heroine),
joined by her plucky, tomboyish assistant Akari
and her cute friend Fanita, pass through a culture
portal via these ruins. Inside they discover its lascivious
secret... The ancient civilization of Sotisthunra
erected this sexual altar for the sake
of the sprawling spermexa that lay dormant...!

These girls may have discovered great history,
but will they survive it!!?

[From DLSite English]