Too much income, not enough expenses.

Looking for some sound advice.

I’ve run out of ideas and looking for genuine and legal (grey is ok) ideas on how to reduce taxable income to the ¥9M 23% tier.
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Service: Business consulting
Income: ¥40M
Taxable income after operating expenses, deductions & blue form deduction: ¥28M

*all expenses are claimed for business use at the maximum amount.

Thank you 🙏