Gen involuntarily traveled from the year 2020 to a distant future where humanity no longer exists. Finding refuge with the Ganko family in Rustling Forest, he must adapt to life without modern conveniences like electricity, gas, running water, television, smartphones, convenience stores, snacks, or video games. He shares this existence and interacts with the Ganko household members, including Ganko, Banban, Chobi, and Game-san.