Generally speaking, the reason why the chin is fleshy is related to fat. If the chin skin is slack, it will be easier to accumulate fat.
But it's not the main reason. In addition to being too fat, facial meridians are blocked, leading to edema and lack of exercise.
Muscle relaxation will make a circle of fat on the chin, which is what we often call a double chin.
You can improve your chin by losing weight or doing exercises and massage with Baubigeat.
More massage can make your chin a little stiff.