The story is set in the fantasy world of "Aria". The main character (a girl knight) is investigating a complicated case of mysterious disappearance of women throughout the city. The investigation led her to a creepy cave, where it was rumored there was a terrible monster. As is usually the case - the rumors turned out to be true, and the main character was trapped by the monster. All the girls were found at that hour, and they all turned out to be honorary knights of the kingdom of Aria. Now the protagonist and numerous girls have to endure the attacks of monsters with tentacles and take their sperm to find a way to save themselves...