Invasion of Japan

Background
The Invasion of Japan was the primary battle of the Second Pacific War, and the only event in that war depicted. It occurred throughout coastal Japan. Prior to the invasion, Genbu Kururugi (father of Suzaku Kururugi) encouraged the Japanese to unite as a single front and defeat the encroaching Britannian presence and protect their homeland. He admitted he was willing to go as far as fighting to the last man if necessary, something Suzaku disagreed with. Suzaku attempted to convince his father to surrender to the superior force and to try and negotiate. Genbu believed that this would dishonor the Japanese, and that was unacceptable regardless of the price. Angered, the two began to fight, and Suzaku attacked his father with a sword, fatally wounding him. Suzaku would then flee the scene, something that would scar him for the rest of his life. After Genbu's death, Japan surrendered easily.

The Battle
The Britannian Naval fleet surrounded the island from the North, East and south, and attacked the island from all positions simultaneously. Drop ship aircraft launched from carriers were used to deposit soldiers and RPI-11 Glasgows behind enemy lines, rendering much of the entrenched military useless. The new Glasgow frames proved themselves an easy match for the scattered soldiers and tanks alike, and the Britannian forces quickly pushed into the countryside. Japanese Forces only managed one success under Lieutenant Colonel Kyoshiro Tohdoh at Itsukushima, a victory that earned him the name Tohdoh of Miracles (奇跡 の 藤堂, Kiseki no Tohdoh). Surrender came not long after the majority of the Japanese forces had been annihilated.

Aftermath
After the war, Britannia renamed the colonized island Area 11, and all Japanese citizens "Elevens." With their victory they also had complete control over the Sakuradite mines in Japan, and with this resource, Britannia would soar in Knightmare frame research.

The Japanese Liberation Front was then formed from the remnants of Japanese military, with the hope to restore Japanese government and free Japan from Britannian occupation.

Aside from the Liberation Front, many smaller but numerous rebel groups quickly rose up over the next several years in resistance to Britannia, most notably the faction led by Naoto Kozuki and later Kaname Ohgi.

Meanwhile, Japanese people who escaped during the invasion formed a government-in-exile led by Atsushi Sawasaki in China. Although this was made to maintain the sovereignty of Japan and restore Japanese rule on their homeland, the Chinese government's support of them was for purely selfish reasons in order to eventually make Japan its puppet state.

Trivia

 * Britannia's invasion of Japan parallels to Japan's annexation of Korea and US occupation of Japan:
 * Both Japan and Korea tried to maintain independence by playing off surrounding large powers with each other and were ultimately taken over in August 10 (CG Japan-2010 atb/Korea-1910 AD). Also both were subjected to brutal forms of suppression and exploitation.
 * Britannia's invasion of Japan and US occupation of Japan dealt with western imperialist powers taking over Japan that met with strong resistance (Black Rebellion and Anpo protests/Bloody May Day/Red Purge) that were suppressed later on after the occupation.