// 税区分, 税表示区分を設定する,
            $TaxInclude = $this->entityManager->find(TaxDisplayType::class, TaxDisplayType::INCLUDED);
            $TaxRule = $this->taxRuleRepository->getByRule($Product, $ProductClass);

            // $TaxRuleを取得出来ない場合は基本税率設定を使用.
            if (null === $TaxRule) {
                $TaxRule = $this->taxRuleRepository->getByRule();
            }

            // 税込表示の場合は, priceが税込金額のため割り戻す.
            if ($TaxInclude->getId() == TaxDisplayType::INCLUDED) {
                $tax = $this->taxRuleService->calcTaxIncluded(
                    $OrderItem->getPrice(), $TaxRule->getTaxRate(), $TaxRule->getRoundingType()->getId(),
                    $TaxRule->getTaxAdjust());
            } else {
                $tax = $this->taxRuleService->calcTax(
                    $OrderItem->getPrice(), $TaxRule->getTaxRate(), $TaxRule->getRoundingType()->getId(),
                    $TaxRule->getTaxAdjust());
            }

            $OrderItem
                ->setTaxType($this->entityManager->find(TaxType::class, TaxType::TAXATION))
                ->setTaxDisplayType($TaxInclude)
                ->setTax($tax)
                ->setTaxRate($TaxRule->getTaxRate())
                ->setRoundingType($TaxRule->getRoundingType())
                ->setTaxRuleId($TaxRule->getId());