There are "clock genes" in the human body, and the day and night skin functions change. It is said that the "clock rhythm" becomes irregular when it is influenced by the day's ultraviolet rays, stress, sleep deprivation, etc., causing rough skin and decreased firmness. "DHC Day & Night Series" is a skin care series focused on "clock genes". It is a line close to the "Skin Rhythm", which requires care required by day and night skin, and supports the skin beautifully for 24 hours.