Is It Wrong to Try to Pick Up Girls in a Dungeon? On the Side: Sword Oratoria, Vol. 13 (manga) — Fujino Omori

Loki Familia's supposed beach vacation has taken a turn toward catastrophe with the appearance of demons from Tiona and Tione's past-the Kali Familia. The unexpected arrival of the Amazonians unhinges Tione, and both sisters must confront memories best forgotten. Before it becomes clear exactly why Kali and her brood have dropped in, tragedy strikes-Lefiya is kidnapped, and Tiona and Tione vanish in the uproar. The goddess Loki's wrath is a thing of horrors, but the Amazonian sisters' ire may just prove worse...