D-Genesis: Three Years after the Dungeons Appeared (Manga) Volume 4 by Tsuranori Kono

Hellhounds and archers await in Keigo and Miyoshi’s first foray into Yoyogi Dungeon’s lower levels. They may be traveling in their souped-up RV, but this is no vacation. Their mission? Obtain Otherworldly Language Comprehension, the elusive skill orb at the center of an international power struggle. Their plan? Use Kei’s dungeon ability, Making—which allows him to plan the next orb drop—and sell the orb to Japan for beaucoup bucks. Unless something stands in the way of their millions... When their plan hits a snag, what will the former researchers do? And are they prepared to face the unknown forces that will cross their path in the unknown depths of the dungeon? The duo is in for an exciting journey!