厚生費 (koseihi) refers to welfare expenses or employee welfare costs in Japan. These expenses are related to the well-being and benefits provided to employees by their employer and are part of the overall personnel costs for a company.

Koseihi can include expenses such as health and safety measures, employee recreational activities, company-sponsored events and social gatherings, subsidies for meals, transportation, and housing, health insurance premiums, and retirement benefits and pension contributions.

These expenses aim to improve the quality of life for employees, promote a healthy and supportive work environment, and enhance employee satisfaction and motivation. By investing in koseihi, companies can foster better employee relations, reduce turnover, and ultimately increase productivity.

社会保障 (shakai hoshō) refers to social security in Japanese. It encompasses a range of public programs and policies designed to provide financial and social support to individuals and families, particularly during times of need. These programs are aimed at ensuring a basic standard of living and protecting citizens against various economic risks.

In Japan, shakai hosho includes various components such as pensions, health insurance, unemployment insurance, and welfare services. Pensions provide income to retirees, disabled individuals, and survivors of deceased workers. Health insurance helps individuals pay for medical expenses. Unemployment insurance provides benefits to those who are unemployed and actively seeking work. Welfare services offer assistance to low-income individuals and families to help cover living expenses.

These programs are funded through contributions from both employees and employers, as well as government funding. The aim of 社会保障 is to promote social stability and well-being by offering financial assistance and services to those in need.

差額ベッド代 (sagaku beddo dai) refers to the additional charge for a hospital room beyond the standard coverage provided by health insurance in Japan. When a patient opts for a more comfortable or private room, they incur this extra cost, which is not covered by insurance.

For example, if you choose to stay in a single room instead of a shared room, the difference in cost is your responsibility. This additional charge for a private or semi-private room, called the sagaku beddo dai must be paid out-of-pocket by the patient.

Importantly, this expense is not eligible for medical expense deductions (医療費控除) under Japanese tax law. Medical expense deductions typically cover essential medical treatments and services, but not optional upgrades such as private room charges

診療報酬 (shinryou houshuu) refers to the payment medical institutions receive for the services they provide. This system is regulated by the government and ensures that healthcare providers are compensated for their work according to standardized rates.

In Japan, the fee structure for medical services is periodically reviewed and revised. The Ministry of Health, Labour and Welfare sets these fees to maintain balance between medical costs and the quality of healthcare services. The fees are detailed in a document known as the 診療報酬点数表 (shinryou houshuu tensuu hyou), or the Medical Fee Schedule, which specifies the points assigned to various medical procedures and services. These points are then converted into yen based on a set conversion factor.

The use of the My Number card (マイナンバーカード) as a health insurance card, known as マイナ保険証 (Myna hokenshou), has also influenced the diagnostic fee structure. For instance, the fees for initial consultations can differ based on whether a My Number card is used, with the aim of encouraging its use by making it more cost-effective for patients​

保険料控除 (hokenryou koujo) refers to insurance premium deductions in Japan. This tax deduction allows individuals to reduce their taxable income by the amount paid in insurance premiums. Eligible premiums typically include those for life insurance, medical insurance, and other specified types of insurance. By claiming hokenryo koujo, taxpayers can lower their overall tax liability, making it a beneficial aspect of personal financial management. To claim this deduction, individuals must provide documentation, such as the certificate of insurance premium deduction, which verifies the premiums paid.