More than 200 years have passed since gates to other worlds first appeared on Earth. Thanks to Skill Cards that grant supernatural abilities, adventurers have become a highly sought-after profession, exploring these alternate realms in search of magical artifacts and rare resources.

After having his first girlfriend stolen by an adventurer, Yusuke Kukutsu decides to become one himself to prove his worth and get back at her. However, the class he receives is Item Master, a non-combat profession widely considered a “useless” or “failure” class.