Episode 5

Crystal (結晶, Kesshō) is the fifth episode of the Welcome to the Slave Harem in the Labyrinth of the Other World anime series.

Plot
Kaga asks Roxanne how to add skills to his equipment and is told he must locate a rare monster skill crystal and have a blacksmith bond it to the equipment. Unfortunately, only dwarves have the blacksmith ability and they are often untrustworthy. Kaga decides to find a trustworthy dwarf and make them a party member. Inside the labyrinth, Kaga learns that Magic Crystals can be filled with monster magic and sold for incredible sums but can take months to accomplish. Purchasing two empty crystals, Kaga learns they can hold magic from 1 million monsters, but most people sell them after 100,000. He also learns labyrinths are alive and grow upwards, so the first floor is actually the lowest, while the strongest monsters are on the top floors. Kaga decides he needs spells that attack multiple targets. As they also require healing spells, both Kaga and Roxanne gain the title of Monk by defeating a monster with their bare hands. At night, they repeat their ritual of bathing each other before making love. The next day, they locate the room of the first floor Boss Monster and head inside to defeat it.