Most shopping in Japan is not refundable, and the scope of tax refund is limited to some products such as home appliances made in Japan, but you know very well that buying cosmetics is not refundable.
However, many Japanese shopping malls cooperate with credit card companies in China, so if you use UnionPay cards, you can enjoy a 15% discount, which is equivalent to giving you tax exemption. Come to Japan to pay more UnionPay cards. Please ask if there is any discount for credit card before payment.
If you want to buy duty-free cosmetics, go to the airport duty-free shop. The price is cheap and there are many varieties.