Cases where a gift tax is imposed

A gift tax is imposed when you receive properties donated by individuals.
When you receive properties donated by a corporation such as a company, income tax instead of gift tax is imposed.
In addition, when you receive the proceeds of life insurance for which you did not pay the insurance premium, or when you receive a benefit due to exemption of debt, etc., you will be deemed to be given a gift and therefore imposed a gift tax.
However, when you receive the proceeds of life insurance for which the decedent had paid the insurance premium for you as the insured person, you will be subject to inheritance tax, not gift tax.
There are two taxation methods for gift tax: calendar year taxation system and taxation system for settlement at the time of inheritance. You can choose the taxation system for settlement at the time of inheritance when certain requirements are met.

1 Calendar year taxation

The gift tax will be imposed after a basic exemption of 1.1 million yen is subtracted from the total value of properties donated to a person in one year from January 1 to December 31. Therefore, the gift tax will not be imposed if the total value of properties donated in one year is less than 1.1 million yen. (In this case, you are not required to file a return for gift tax.)

2 Taxation by settlement at the time of inheritance

For gift recipients who selected the taxation system for settlement at the time of inheritance, gift taxes are imposed after a special deduction of 25 million yen is subtracted from the total value of properties donated in one year from January 1 to December 31.
This special deduction can be applied only when a taxpayer files a return for gift tax within the statutory due date.
If this special deduction was applied to part of the amount prior to the previous year, the remaining amount after subtracting it from 25 million yen will be the limit for special deduction.

3 Tax declaration and payment

If the gift tax is imposed or the taxation system for settlement at the time of inheritance is applied, it is necessary for the person receiving the properties to file a return and pay tax between February 1 and March 15 of the year following the year in which the properties are received.
If the taxation system for settlement at the time of inheritance is applied, even if there is no tax amount to be paid, it is necessary to file a return between February 1 and March 15 of the year following the year in which the properties are received.
While taxes are generally paid in cash at once, postponement of tax payment is allowed as a special tax payment system for gift taxes.
This allows a taxpayer to pay taxes in installments over several years.
Those who wish to postpone tax payment must submit application forms and other documents to Tax Office by the due date for tax return and obtain permission.

出典：国税庁ホームページ（http://www.nta.go.jp/english/taxes/others/02/15002.htm）