The Nishinomaru of Himeji Castle was built in the early Edo period as the residence of Sen Hime, the grandson of Tokugawa Ieyasu. Sen Hime was the wife of Toyotomi Hideyori, but was rescued after the destruction of the Toyotomi family in the Osaka Summer War (1615). She remarried to Honda Tadatoki in 1616 and moved to Himeji Castle the following year. The Nishinomaru was newly established for her. In the Nishinomaru, a “cosmetic turret” was built as Sen Hime's living space. This two-story turret with tatami mats inside was used as the Okugoden (inner palace). It is also said that the morning sun shines through the window on the east side, and that this was used by Sen Hime when she applied her makeup. On the east side of the Nishinomaru, there is a long corridor called “Watagura (long station),” which stretches for about 240 meters. Inside this corridor are a series of rooms for the maids and servants of Sen Hime, which served as their living space. The entire Nishinomaru was designed as a separate area surrounded by stone walls, with a size and structure befitting Sen Hime's status. Its main purpose, however, was not defense, but rather to serve as a place of residence and living for Sen Hime. Today, the Nishinomaru is preserved as part of Himeji Castle, telling visitors the history of the period and the story of Sen Hime.