It is in every human being’s nature to live side by side with fellow human beings to try to maintain offspring by entering into marriages. The presence of a child in a marriage is not only viewed as a consequence of a biological relationship between a husband and wife, but rather, is a natural desire of every husband and wife to have an offspring as an heir to their assets and wealth. However, there are several husband and wives which encounters a hard time to have offspring, therefore, it is common for husband and wives to conduct adoptions if their marriage does not possibly allow them to have offspring. Within the Inheritance Law, an heir pursuant to the Indonesian Civil Code is differentiated into two, namely Inheritance by way of Ab Intestato which is an heir based on Law and Inheritance by way of Testamentair which is an heir due to appointment within a will or testament. Within the civil inheritance legal system, on the other hand, there exists absolute portion (legitime portie) which is useful to protect the other heirs’ portion. Therefore, within this research, data collection is conducted by using case approach towards biological siblings which demands their inheritance distribution since one of the party feels that their legitime portie has been violated, therefore the will of grant (hibah wasiat) conducted by the Inheritor shall be annulled to satisfy the legitime portie of the heir. The explanation of grant as an agreement which shall be annulled unilaterally to satisfy the right of the heir.