Title: Politics of Japan
Content:   The politics of Japan are conducted in a framework of a multi-party bicameral parliamentary representative democratic constitutional monarchy in which the Emperor is the Head of State and the Prime Minister is the Head of Government and the Head of the Cabinet, which directs the executive branch. Legislative power is vested in the National Diet, which consists of the House of Representatives and the House of Councillors. The House of Representatives consists of eighteen standing committees ranging in size from 20 to 50 members and The House of Councillors has sixteen ranging from 10 to 45 members. Judicial power is vested in the Supreme Court and lower courts, and sovereignty is vested in the Japanese people by the Constitution. Japan is considered a constitutional monarchy with a system of civil law.
Title: Constitutionalism
Content:  On May 3, 1947, the sovereign state of Japan has maintained a unitary parliamentary constitutional monarchy with an Emperor and an elected legislature called the National Diet.
Title: Japan
Content:  Japan is a unitary state and constitutional monarchy in which the power of the Emperor is limited to a ceremonial role. Executive power is instead wielded by the Prime Minister of Japan and his Cabinet, whose sovereignty is vested in the Japanese people. Naruhito is the Emperor of Japan, having succeeded his father Akihito upon his accession to the Chrysanthemum Throne in 2019. Japan's legislative organ is the National Diet, a bicameral parliament. It consists of a lower House of Representatives with 465 seats, elected by popular vote every four years or when dissolved, and an upper House of Councillors with 245 seats, whose popularly-elected 
Title: Chrysanthemum Throne
Content:   Japan is the oldest continuing hereditary monarchy in the world. In much the same sense as the British Crown, the Chrysanthemum Throne is an abstract metonymic concept that represents the monarch and the legal authority for the existence of the government. Unlike its British counterpart, the concepts of Japanese monarchy evolved differently before 1947 when there was, for example, no perceived separation of the property of the nation-state from the person and personal holdings of the Emperor. According to legend, the Japanese monarchy is said to have been founded in 660 BC by Emperor Jimmu; Naruhito is the 126th monarch to occupy the Chrysanthemum Throne. The extant historical records only 
Title: Childbirth in Japan
Content:  Since its constitution was adopted in 1947, Japan has been a parliamentary government with a constitutional monarchy. The monarchy is hereditary while the prime minister must be elected by the Diet, or a bicameral legislative branch consisting of the House of Councilors and House of Representatives. Japanese local administration is by prefecture. The country is divided into 47 prefectures, each of which is further subdivided into cities with respective wards and blocks. Suffrage is granted at age 20 Japan boasts the fourth largest GDP in the world after the European Union, the United States, and China. While Japan was for centuries a largely agricultural economy, the percentage of the total labor force shifted dramatically in the twentieth century from agriculture to industrial occupations. Consequently, Japan must 
Title: Outline of Japan
Content: Form of government: parliamentary multi-party representative democratic constitutional monarchy ; Capital of Japan: Tokyo ; Elections in Japan ; Imperial House of Japan (Imperial family) ; Imperial Guard of Japan ; Imperial Household Law ; Imperial Household Agency ; Civil service of Japan ; Japanese public corporations ; Independent administrative institutions of Japan ; Political parties in Japan ; Government-business relations in Japan ; Human rights in Japan ; Mass media and politics in Japan ; Monetary and fiscal policy of Japan ; Political funding in Japan ; Political extremism in Japan ; Taxation in Japan ; Health care system in Japan ; Social welfare in Japan  
Title: Government of Japan
Content:  The Government of Japan consists of legislature, executive and judiciary branches and is based on popular sovereignty. The Government runs under the framework established by the Constitution of Japan, adopted in 1947. It is a unitary state, containing forty-seven administrative divisions, with the Emperor as its Head of State. His role is ceremonial and he has no powers related to Government. Instead, it is the Cabinet, comprising the Ministers of State and the Prime Minister, that directs and controls the Government and the civil service. The Cabinet has the executive power and is formed by the Prime Minister, who is the Head of Government. He is designated by the National Diet and appointed to office by the Emperor. The National Diet is the legislature, 
Title: Prime Minister of Japan
Content:  Before the adoption of the Meiji Constitution, Japan had in practice no written constitution. Originally, a Chinese-inspired legal system known as ritsuryō was enacted in the late Asuka period and early Nara period. It described a government based on an elaborate and rational meritocratic bureaucracy, serving, in theory, under the ultimate authority of the Emperor; although in practice, real power was often held elsewhere, such as in the hands of the Fujiwara clan, who intermarried with the Imperial Family in the Heian period, or by the ruling shōgun. Theoretically, the last ritsuryō code, the Yōrō Code enacted in 752, was still in force at the time of the Meiji Restoration. Under this system, the Daijō-daijin (太政大臣) was the head of the Daijō-kan (Department of State), the 
Title: Government of Japan
Content:  the Emperor is not the source of sovereign power and the government does not act under his name. Instead, the Emperor represents the State and appoints other high officials in the name of the State, in which the Japanese people hold sovereignty. Article 5 of the Constitution, in accordance with the Imperial Household Law, allows a regency to be established in the Emperor's name, should the Emperor be unable to perform his duties. On November 20, 1989, the Supreme Court ruled it doesn't have judicial power over the Emperor. The Imperial House of Japan is said to be the oldest continuing hereditary monarchy in the world. According to the 
Title: Modern republicanism
Content:  Anti-monarchism in Japan was a minor force during the twentieth century. The Japanese Communist Party is the most prominent advocate of a non-monarchic system and has in the past demanded the abolition of the emperor system outright.

Question: what kind of monarchy does japan have?
Answer: Constitutional monarchy.