Based on the manga by Koio Minato.

The main character is a senior who attends Rinin High School; the only school among the mountain town of Rinin City. The main character, who is the student president of the high school, has another hidden persona. The persona as head of the “Gang Rape Club”…
A dark ceremony existed that had been handed down for thousands of years in the old town of Rinin; the name of the ceremony, in particular, in the oldest of records. That ceremony, enacted to protect the region from disease and crop failure as a curse from the region’s guardian deity, Hime Iwanaga, occurs in the evenings between the new moon and full moon, in which a maiden is disguised as Konohanasakuyabime and gangraped to appease Hime Iwanaga’s anger. In regards to the maiden, there must be an important man participating in the gang rape, in other words, that man must be related in blood to their wife or lover, mother or daughter, younger sister or older sister, and the like, and after the gang rape, if a pregnancy occurs, Hime Iwanaga’s anger is abated, and a good harvest and safety upon the region will be promised. However, if a pregnancy does not occur for the sake of suppressing Hime Iwanaga’s anger, the maiden is supposed to be covered with semen, and floated down the river alive, as a sacrifice.
And now – after the Tashio era, the ceremony itself had vanished into the dark history, but had still continued on at Rinin High School; the cruel, improper traditions being inherited over into a secret society through actions carried out by the Gang Rape Club. For generations, the student president of the High School has served as the head of the Gang Rape Club, not allowing even one day to pass uneventfully, submerging numerous women to the dark, suffocating pleasure.

Who will be the next fare? What lonely woman can resist the forbidden thrill in the back seat of a taxi cab? As the taxi cruises the back streets what illicit acts could possibly be taking place in the shadows?

When Mishiro was small, half of his soul was eaten by a toothed deity. Since then he has had to deal with spirits called kotowari that reside in the darkness of the souls of people who are related to him, no matter how distant.
Kotowari are soul fragments created from a person’s suffering and they can normally only be seen, heard and touched by that individual. Even if the kotowari is destroyed, it will keep respawning unless the cause of the suffering is resolved. Shortly after transferring to a school in a history-laden sightseeing town, Mishiro encounters a kotowari and decides to search for its owner.
However, there isn’t just one kotowari as many other girls harbour their own suffering.

Got a case you can’t crack, a mystery you can’t solve? Then call on the Goddess Detective Agency where the busty Karen and her wild partner, Rio, will see to your every need!
When this beautiful detective duo takes on a new case involving drugs and rape, it brings back painful memories for Rio whose sister was killed by a gang of sex-starved drug dealers. Could the same gang be responsible for this new threat? Hot-headed as she is, Rio must learn to control her anger in order to uncover the truth. Meanwhile, Karen’s constant exposure to the lurid details of the case are causing her to lose control of her own insatiable lust.
Will this pair of sexy sleuths be able to conquer themselves in time to solve the case? Or will the hunters become the prey?

On the day Princess Elfina of Fiel was to marry Prince Kwan, the Valdland army, led by Prince Viceard Balbacil attacked both Kwan’s party and Firan castle.
In the resulting Valdland victory, Kwan is seriously injured and Elfina, along with all of the other women of Fiel, are forced into sexual subjugation. Viceard’s plans are turned upside down, however, by the arrival of his first-love turned step-mother Marna, who brings Viceard news that his father plans to frame and kill him.
With the moderating force of Marna’s presence on him, Elfina is exposed to Viceard’s softer side, as the king’s arrival and Kwan’s escape promise to shake the occupied kingdom of Fiel.

It is now the year 2010. The reprehensible and secret brotherhood known as the Last Molester Train has been driven underground once again, its three year reign of sexual predation extinguished under the militant ultra-feminist organization known as Raven Guard. However all is not yet lost. The Last Molester Train continued to search for a savior who could restore their patriarchy to glory, and at long last that man has been found. Revered under the pseudonym of Zin, this legendary molester defied the Raven Guard and defiled many a lovely flower under their watch. A single careless mistake is all it took catch him… but the brotherhood will not let a comrade-in-arms fall so easily.

3D Hentai by studio GGB.
No plot; just what happens when you summon two hot Succubi. :>