noun
Maritime Staff Office
The staff office of the Japan Maritime Self-Defense Force (JMSDF), responsible for operations, planning, and administration.
海上幕僚監部は、海上自衛隊の作戦や訓練を統括する。
The Maritime Staff Office oversees operations and training of the Japan Maritime Self-Defense Force.
Compound of 海上 (maritime) + 幕僚 (staff) + 監部 (supervisory department). The term follows the naming pattern of the Self-Defense Forces' staff offices.