Go Yang-sun, who was plump from birth, couldn't resist her parents' pressure and entered Dr. Park's diet club. Dr. Park looks somewhat suspicious, but her background is clearer than anyone else's. This place, which boasts a 100% success rate, has only one condition for discharge: ‘You must lose all of your target weight!’ Will Yangsun, who weighs over 100kg, be able to successfully diet and leave this place with a smile?!