D.S.E 絶対深姦（D. S. E Zettai Shinkan）

Gangbang, torture, hideous tentacles... endless ecstasy and enormous wet cumshots...
Atrocity and assault in the claustrophobic confines of deep sea... Erotic Horror AVG!

D.S.E. Deep Sea Existence -Total Drench-

The "Beluga" is a deep sea vessel for exploration. Ryusha (the heroine) joined their expedition as an ATB operator and diver. Down here in the darkness of the ocean, the corpse of a strange creature has been discovered. However you look at it, it appears... like a dragon. When time runs short they have to abandon it, and make plans to move on. But that night a murder happens on the Beluga...

Unable to turn back, Ryusha and her crew are now in it for
their lives in a downward spiral of madness thousands of meters
below the surface. Terror and jealousy rain down on the intelligent beauty
as sexual atrocity takes control... something dreadful and alien is emanating
from that quiet carcass... that dragon...

In the grips of lust and bloody horror, who will survive?
What is the true form of this deep monster...!?

[From DLSite English]