Warashibe Chouja to Neko to Hime: Uchuu to Chikyuu no Koueki Skill de Nariagari!? Shachou! Eiyuu?…Uchuu Kaizoku!?

In Tokyo, where dungeons have appeared, a poor college student, Tombo, suddenly awakens to a skill... It's the divine skill of 'Cosmic Trading,' which allows him to exchange items from faraway space with items from Earth! Together with Mars, a space cat exchanged for orange peels, he starts a business to get some quick cash—and it becomes a huge hit with dungeon adventurers, quickly growing into something bigger…!? Through a series of trades, he somehow even acquires beautiful girls!? And he might even get his hands on a giant robot, a man's ultimate dream…?