One evening, a new client comes to the dietitian Tomoatsu Naoe. Her name is Elfuda, and she is an elf who has gained quite a bit of weight during her time in the human world. Elfuda needs Naoe’s help to lose the extra pounds and gain the opportunity to return to her home world. While Tomoatsu is helping her lose weight, many other overweight mythical creatures come to him for help.