Following the arrival of the Portuguese in Japan, daimyos competed for control of foreign trade and technology. Himeji Castle, a symbol of feudal power, became a strategic center for clans seeking to gain influence.

In The White Castle Duel, two clans compete to exert their influence in the White Heron's court, managing resources and building engines. On each turn, you will use their lamp tokens to obtain resources and activate actions. Among the actions available, you can buy and upgrade influence cards, place clan seals on gardens and training grounds, move your courtier between circles of influence, or trade with the Portuguese. These actions will allow you to accumulate a series of icons — flags, katanas, kabutos, and origami figures — that will reward you with points, and whoever ends up with the most points wins.