In an Earth that has opened its borders to a variety of aliens, Kumika is considered an oddity by her coworkers, being an alien that doesn’t eat or drink at all, instead sustaining herself solely on the air's nutrients. Due to this ability and her poverty-ridden past, Kumika regularly rejects after-work invitations to restaurants and bars, and seeks to spend her time on Earth solely to work—causing her coworkers to perceive her as a cold person.

However, Kumika finds that she is unable to keep up a work-only lifestyle, as she ends up collapsing at work from exhaustion one day. Noticing that she is malnourished, her coworker Chihiro serves Kumika her first meal ever: a bowl of hot udon. Instantly revitalizing her, Kumika awakens to the joys and pleasure that food has to offer, with a stomach that growls and craves for flavors and textures to explore—thus begins Kumika's journey to eat the various cuisines that Earth has to offer.