Don Quijote Tax free deduction not exactly 10%?

Just checked back a Donki receipt.

Total paid ¥20148

tax deducted ¥1825

I don't get it. If my full price was ¥20something thousand, why isnt the 10% tax deduction ¥2000and something?

every item on the receipt has the Star icon meaning tax deductible

by OddCowboy123