Eirei refers to the spirits of Japan's war dead, honored collectively as ancestral and national spirits within Shinto tradition. They are enshrined and commemorated at sites such as Yasukuni Shrine and various local shrines, where memorial rites are performed to honor their sacrifice and service to the nation. The veneration of Eirei reflects broader Japanese ancestral customs of honoring the deceased, though interpretations of their significance remain a subject of ongoing historical and political discussion.