Based on the erotic game by Lune.

"Even if you're an executive, failure must be punished."

Katsuma, Great Lunarium's lone male executive, is the one who is tasked with enforcing this rule. Abusing his authority, he inflicts sexual pleasure hell on the female executives who fail in their tasks. Over the years, he had built up a deep enmity against these arrogant women who regularly bullied him, but now, it is time for his revenge. His next targets are:
Ephanatica - Extremely loyal to Great Lunarium, her appearance is that of a demon, compensation for her powers; and
Diana - An earthling who betrayed her people, whose breasts are the largest amongst the executives.