Research on memory has demonstrated that remembering material can cause forgetting of related information, which is known as retrieval‐induced forgetting (RIF). Macrae and Roseveare identified “self” as one of the boundary conditions of this effect in the Western cultural context, showing that RIF was eliminated when material was encoded to be related to the self (known as self‐referential effect), but not to significant others. In this study, we predicted and found that significant others could be another boundary condition in Japanese cultural contexts in which self and agency are more interdependent or conjoint; RIF was observed neither under best‐friend‐related encoding nor under family‐related encoding in Japan. The effect of significant others is found uniquely in Japanese cultural contexts, suggesting that the cultural model of self has significant power in the spontaneous system of memory.