Japan subtracts skin care and washes its hair once every three days. Because Japanese subtraction skin care refers to the minimalist aesthetic concept of slimming, makeup and clothing, according to relevant data, Japanese subtraction skin care hair is washed 2-3 times a week, with an average of 3 days. But it depends on personal hair quality, hair tail, activity and other factors. Some people may increase or decrease the shampoo interval because of scalp allergy, incomplete cleaning and other reasons.