He was born in the castle town of Kumamoto, the third son of the Iida family, retainers of the Nagaoka house, chief vassals of the Kumamoto domain. His father was a low-ranking samurai with a small stipend. From childhood he was praised as a prodigy, and it is said he never skipped reading even while helping with chores. His diligence caught the eye of his lord, Nagaoka Korekata.
Recognized by his lord Nagaoka Korekata, he entered the Nagaoka family school, the Hitsuyūdō, and studied there for five years. He then joined the school of the Confucian scholar Kinoshita Isan, where he stood out and drew notice as a brilliant student alongside Takezoe Shin'ichirō and others. A boy from a humble family was opening his path through learning.
On Kinoshita Isan's recommendation, though only a retainer's retainer, he was chosen as a boarding student at the Jishūkan, the Kumamoto domain school. He studied Confucianism deeply, especially Zhu Xi learning, but valued practical learning useful for real politics rather than mere memorization. His days were filled with reading and annotation.
He visited the thinker Yokoi Shōnan, then under house confinement, debated with him and recorded the conversation. Against Shōnan's call to open the country and expand trade, the young Inoue argued that it was doubtful Japan could deal well with foreign nations of different languages and institutions. He would later change his views greatly.
After being adopted into the Inoue family, he moved to the French-language school the shogunate opened in Yokohama. But the turmoil of the return of power to the emperor and the Boshin War interrupted his study, and he went home. He tried to study in Nagasaki as well but gave up on the domain's orders, and he marched to the northeast with Kumamoto troops, keeping a diary.
He entered the Meiji government's Ministry of Justice and, because he could speak French, went to Europe as a member of a mission studying judicial systems. In Germany he encountered a school of law that respected each nation's history and customs, and came to believe that Japan should build on its own traditions rather than simply copy foreign law.
After returning, he was recognized for his talent and employed by Ōkubo Toshimichi. He accompanied Ōkubo in putting down the Saga Rebellion, and then followed him to Qing China for negotiations over the expedition to Taiwan, where he was entrusted with drafting the negotiating documents. As a young official, he began working directly on matters of state.
After Ōkubo's death he became Iwakura Tomomi's chief adviser. When a British-style constitutional plan was put forward, he argued for promptly drafting a Prussian-style constitution with strong imperial powers and worked to build a majority within the government. With the crisis of 1881 that year, the government's course for drafting a constitution was settled.
Serving as Itō Hirobumi's brains, he drafted the imperial words promising when a national assembly would open, and was also involved in drafting the Imperial Rescript to Soldiers and Sailors issued that year. He even accompanied missions to settle incidents in Korea. As an expert in law and writing, he was relied on at every important juncture of government.
At Itō Hirobumi's villa on Natsushima and elsewhere, he joined Itō, Itō Miyoji and Kaneko Kentarō, and the four debated again and again to refine the draft constitution. Reading deeply in the Kojiki, he worked to bring Japan's traditional ideas of rule into the constitution. He also reportedly drew on the views of foreign advisers.
As chief secretary of the Privy Council, the emperor's advisory body, he supported its deliberations, and that year the Meiji Constitution was promulgated. As a legal expert he also helped draft the Imperial House Law and other statutes. Though conservative, he is said to have valued the constitutional principle of protecting the people's rights under law.
At the request of Prime Minister Yamagata Aritomo, he drafted the Imperial Rescript on Education, setting out the basis of moral education. Believing it should avoid religious and philosophical coloring and stay neutral, he refined the wording in consultation with Motoda Nagazane, a Confucian scholar also from Kumamoto. The rescript was issued that year and long served as a pillar of school education.
He became education minister in the second Itō cabinet and, though suffering from tuberculosis, devoted himself to reforming the school system. He promoted state subsidies to expand vocational education and reorganized the higher school system, trying to open paths other than university. He sometimes visited schools himself to see conditions firsthand.
After resigning as minister, he convalesced at his villa in Zushi, but his illness worsened; shortly before his death he was made a viscount, and then he passed away. Even his opponent Nakae Chōmin praised him as earnest and free of brazenness. As a man who sketched the framework of the Meiji state, he remains a subject of study today.
Yokoi ShōnanIwakura TomomiŌkubo ToshimichiYamagata AritomoItō HirobumiNakae Chōmin
Niijima JōInoue MasaruSaigō TsugumichiMutsu MunemitsuNiijima YaeNakae ChōminMori ArinoriTōgō Heihachirō
People of the Meiji period ・ People by period
Based on facts found in textbooks and biographies. Uncertain points are marked as such.