Osaka Castle is a Japanese castle in Chuo-ku, Osaka, Japan. The castle is one of Japan's most famous, and played a major role in the unification of Japan during the sixteenth century of the Azuchi-Momoyama period.
In 1583 Toyotomi Hideyoshi commenced construction on the site of the Ikko-ikki temple of Ishiyama Hongan-ji. The basic plan was modeled after Azuchi Castle, the headquarters of Oda Nobunaga. Toyotomi wanted to build a castle that mirrored Oda's, but surpassed it in every way: the plan featured a five-story main tower, with three extra stories underground, and gold leaf on the sides of the tower to impress visitors. In 1585 the Inner donjon was completed. Toyotomi continued to extend and expand the castle, making it more and more formidable to attackers. In 1597 construction was completed and Hideyoshi died. Osaka Castle passed to his son, Toyotomi Hideyori.