You can choose whichever is more advantageous between the casualty loss deduction and the Disaster Relief Law. High-income earners cannot use this (income exceeding 10 million yen). Depending on income, this is a powerful system that can fully exempt income tax. To apply for the income tax reduction/exemption under the Disaster Relief Law, you must indicate on your tax return that you are applying, along with details of the damage and the amount of loss. Filing a tax return is required.