The Onin War is a key event. It led to the Sengoku period, a time of great chaos and warfare in Japan. This was a time when many warlords fought for supremacy, and out of this chaos, the shogunate system started to re - emerge in a more consolidated form. Another event was the arrival of the Portuguese in the 16th century. This brought new technologies and ideas, and the shogun had to deal with the influence of these foreign elements on Japanese society.
The real - story events include the rise of the Minamoto clan which led to the first shogunate. This was a significant development as it changed the power dynamics in Japan. The shogunates also had to face internal rebellions, such as the Shimabara Rebellion in the 17th century. This was a peasant uprising against the Tokugawa shogunate's harsh rule. It was an indication of the social tensions that existed during the shogunate era. Additionally, the diplomatic relations with neighboring countries, like Korea and China, were also part of the real - story context. These relations influenced trade, cultural exchange, and sometimes military posturing among the shogunates.