Short answers, pulled from the story.
The Empire of Japan, also known as the Japanese Empire or Imperial Japan, was the period of Japanese history spanning 79 years. It began with the Meiji Restoration on the 3rd of January 1868 and ended with the ratification of the Constitution of Japan on the 3rd of May 1947.
On the 3rd of January 1868, Satsuma-Choshu forces seized the imperial palace in Kyoto, and the next day they had the fifteen-year-old Emperor Meiji declare his own restoration to full power. This followed Tokugawa Yoshinobu's resignation of his post and authority to the emperor on the 9th of November 1867.
Japan pursued the policy of fukoku kyohei, meaning Enrich the Country, Strengthen the Armed Forces, and dispatched the Iwakura Mission in 1871 to study Western systems. It recruited more than 3,000 Westerners to teach science, mathematics, technology, and languages, and modeled its judicial system and constitution on Prussia.
Japan emerged as a great power through the First Sino-Japanese War of 1894 to 1895, the Boxer Rebellion in 1900, the Russo-Japanese War of 1904 to 1905, and World War I. In the Russo-Japanese War, Admiral Togo Heihachiro's navy annihilated the Russian Baltic fleet at the Battle of Tsushima.
Japan formally annexed Korea in August 1910 and ended its occupation 35 years later with the surrender of Japan in World War II on the 2nd of September 1945. Russia's defeat in the Russo-Japanese War had cleared the way for the outright annexation in 1910.
Historians debate the term. The absence of a single dictator and a mass fascist movement led scholars to propose alternatives such as para-fascism, militarism, corporatism, totalitarianism, and police state. Robert Paxton judged Japan better understood as a military dictatorship, while Roger Griffin called it para-fascist.
The Empire of Japan ended after defeat in World War II, with formal surrender issued on the 2nd of September 1945 under the Potsdam Declaration. A new Japanese constitution was enacted in 1947, officially ending the Japanese Empire and forming modern Japan.