One-piece swimsuits can't be worn as underwear. Because the general swimsuit does not adjust or fix the chest shape, the breasts may droop and lose concentration after wearing for a long time.

But in general underwear, it has the function of adjusting or concentrating the whole breast to the middle. There are also individual underwear, such as three rows of three buttons and three rows of four buttons. Most of these underwear have the function of collecting auxiliary milk, while one-piece swimsuits do not have this function.