Gu Pan'er, an overweight noble consort weighing 200 jin, unexpectedly becomes bound to a weight-loss system. To save her life, she is forced to complete a series of outrageous missions, leading to hilarious scenes such as openly talking back to the emperor and tackling him to do push-ups. Her antics repeatedly throw the normally aloof Emperor Qin Jichu into disarray. While slimming down and transforming herself with the system, she gradually develops feelings for Qin Jichu despite their constant clashes. Together, they overcome the schemes of rival concubines, rebellions plotted by powerful relatives of the imperial family, and other crises. In the end, Gu Pan'er undergoes a stunning transformation, and Qin Jichu dismisses his entire harem and makes her his one and only empress. The two remain devoted to each other and finally find their happily ever after.