Mamono Musume: Spider & Harpy & Cyclops

In the midst of the war between humans and monsters, the spider princess Arachne was bored out of her mind. She spent every day in her castle in the middle of nowhere, watching the same boring events unfold. She even tried to provoke her assistants, the harpy Rupuia and the cyclops Cyc, into some exciting entertainment, but to no avail. Finally, in desperation, Arachne came up with a new plan to get rid of her boredom—a summoning ritual.

Her assistants tried to dissuade her, warning her of the dangers, but nothing could stop Arachne. She opened a portal to another world and released something terrible from it... a human!

This human, named Hibiki, is terrified of his new surroundings and begs to be sent back home. But the portal is one-way! And to make matters worse, there aren't enough bedrooms in the castle for all four of them! What will become of Hibiki, who must now live (and sleep) with these three otherworldly girls?