Japan Post Holdings Co., Ltd. is a Japanese publicly traded conglomerate headquartered in Kasumigaseki, Chiyoda, Tokyo. It is mainly engaged in postal and logistics business, financial window business, banking business and life insurance business. The company offers letters and goods transportation services, stamp sales, deposits, loans, and insurance products.

Kasumigaseki is a district in Chiyoda Ward in Tokyo, Japan. It is the location of most of Japan's cabinet ministry offices. The name is often used as a metonym for the Japanese government bureaucracy, while Nagatachō refers to the elected government or the legislative branch. Kasumigaseki Station was one of the stations affected during the Tokyo subway sarin attack.