Japan is a parliamentary democracy with a hereditary Emperor who is a symbol and nothing more. Voters elect the two
houses of the Diet; the Diet chooses the Prime Minister; the Cabinet answers to the Diet. Below that, 47 prefectures
and 1,718 municipalities elect their own governors, mayors and assemblies directly.
I
Chapter I · Arts. 1–8
The Emperor 天皇
Head of a constitutional monarchy, but with no political power: every act of state needs the Cabinet's advice and approval.
“The Emperor shall be the symbol of the State and of the unity of the people, deriving his position from the will of the people with whom resides sovereign power.”
Article 1
“The Emperor shall perform only such acts in matters of state as are provided for in this Constitution and he shall not have powers related to government.”
Article 4(1)
Emperor
Naruhito 徳仁, since 1 May 2019
Term
For life; the throne is dynastic and succession follows the Imperial House Law passed by the Diet (Art. 2)
Chosen by
Heredity — not by any election
Acts
“The advice and approval of the Cabinet shall be required for all acts of the Emperor in matters of state” (Art. 3).
He appoints the Prime Minister as designated by the Diet and the Chief Judge of the Supreme Court as
designated by the Cabinet (Art. 6). With the Cabinet's advice he promulgates laws and treaties, convokes
the Diet, dissolves the House of Representatives and proclaims general elections (Art. 7).
II
Chapter IV · Arts. 41–64
The National Diet 国会
“The highest organ of state power, and … the sole law-making organ of the State” (Art. 41). Two elected houses — but they are not equals.
House of Representatives 衆議院
Speaker Eisuke Mori 森英介, since 18 Feb 2026
Seats
465: 289 single-member districts and 176 by party list in 11 regional blocks; 233 is a majority
Term
Four years, “terminated before the full term is up in case the House of Representatives is dissolved” (Art. 45). A general election must follow within 40 days of a dissolution (Art. 54).
Chosen by
Voters, with two ballots: a district candidate and a party
How
First past the post in each district, D'Hondt in each block; a district loser can return on the list. How the ballots work →
House of Councillors 参議院
President Masakazu Sekiguchi 関口昌一, since 11 Nov 2024
Seats
248; 125 is a majority
Term
“Six years, and election for half the members shall take place every three years” (Art. 46). It cannot be dissolved; it is closed while the lower house is dissolved, though the Cabinet may call an emergency session (Art. 54(2)).
Chosen by
Voters, by prefectural district and a nationwide party list
How
No member may sit in both houses (Art. 48). Each house needs one-third of its members present to do business — 155 and 83 — and decides by a majority of those present (Art. 56).
The Diet today · caucuses 会派
Coalition 351 of 465 · 120 of 248
The LDP–Ishin coalition (自維連立) has a two-thirds majority in the lower house but
no majority in the upper — a “twisted Diet” (ねじれ国会). Build your own →
The superiority of the House of Representatives · 衆議院の優越
Art. 59BillsA bill the upper house rejects or amends becomes law if the lower house passes it again by two-thirds of the members present. Sixty days of upper-house inaction may be treated as rejection.
Art. 60The budgetGoes to the lower house first. If the houses disagree and a joint committee fails, or the upper house does not act within 30 days, the lower house's decision is the Diet's.
Art. 61TreatiesThe same rule as the budget applies to the Diet's approval of treaties.
Art. 67The Prime MinisterIf the houses designate different people and a joint committee fails, or the upper house names no one within ten days, the lower house's choice prevails.
Art. 69ConfidenceOnly the House of Representatives can bring down a Cabinet, by a non-confidence resolution — and only it can be dissolved.
“A bill which is passed by the House of Representatives, and upon which the House of Councillors makes a decision different from that of the House of Representatives, becomes a law when passed a second time by the House of Representatives by a majority of two-thirds or more of the members present.”
Article 59(2)
Try it · Arts. 59–61
Pass it through both houses.
Starts from today's Diet: every member present and the LDP–Ishin coalition voting yes. Move the sliders to try other
splits. The House of Councillors can delay, but in the end the House of Representatives decides.
III
Chapter V · Arts. 65–75
The Cabinet 内閣
“Executive power shall be vested in the Cabinet” (Art. 65), which “shall be collectively responsible to the Diet” (Art. 66(3)).
Prime Minister 内閣総理大臣
Sanae Takaichi 高市早苗, since 21 Oct 2025
Term
No fixed term. The Cabinet resigns en masse when the post falls vacant and at the first sitting of the Diet after every general election (Art. 70), so the Diet designates again each time.
Chosen by
The Diet, “from among the members of the Diet” (Art. 67)
How
Each house votes; designation “shall precede all other business”. The Emperor then appoints (Art. 6). Sanae Takaichi first took office on 21 Oct 2025 and was designated again on 18 Feb 2026, after the general election.
Ministers of State 国務大臣
Chief Cabinet Secretary Minoru Kihara 木原稔
Chosen by
The Prime Minister, who “may remove the Ministers of State as he chooses” (Art. 68)
Rules
“A majority of their number must be chosen from among the members of the Diet” (Art. 68); the Prime Minister and ministers “must be civilians” (Art. 66(2)).
Coalition
LDP–Ishin coalition, since 21 Oct 2025. Ishin supported the government from outside the cabinet until the 17 September 2026 reshuffle, when Hiroshi Nakatsuka (中司宏) became a minister.
“If the House of Representatives passes a non-confidence resolution, or rejects a confidence resolution, the Cabinet shall resign en masse, unless the House of Representatives is dissolved within ten (10) days.”
Article 69
Try it · Art. 67
When the houses choose differently.
Each house votes for a Prime Minister. If they pick different people, a joint committee of ten members from each
house tries to agree; if it cannot, or the upper house names no one within ten days, the lower house's choice wins.
House of Representatives designates
House of Councillors designates
Joint committee
30 July 1998
Obuchi over Kan
With the upper house divided after its 1998 election, the House of Councillors chose opposition leader Naoto Kan in a runoff. The House of Representatives had chosen Keizō Obuchi, and its choice became the Diet's.
The lower house re-designated Sanae Takaichi on the first ballot. In the upper house, where the LDP and Ishin caucuses are short of a majority, no one won a majority on the first ballot; she won the runoff against Junya Ogawa, so both houses agreed.
Judges are appointed, not elected — but every Supreme Court justice faces the voters at a general election.
Supreme Court 最高裁判所
Chief Justice Yukihiko Imasaki 今崎幸彦, since 16 Aug 2024
Seats
15: the Chief Justice and 14 justices (Court Act Art. 5)
Term
Until age 70 (Court Act Art. 50); removable only by public impeachment or a finding of incapacity (Art. 78)
Chosen by
The Cabinet — the Chief Justice designated by the Cabinet and appointed by the Emperor (Art. 6(2))
Power
“The court of last resort with power to determine the constitutionality of any law, order, regulation or official act” (Art. 81). Lower-court judges are appointed by the Cabinet from the Supreme Court's list for ten-year terms (Art. 80).
National review · 国民審査 · 8 Feb 2026
Keep or dismiss?
Each justice is reviewed at the first general election after appointment, and again after ten years (Art.
79(2)). Voters write × against a justice they want dismissed and leave the box blank otherwise (Review Act Art. 15); a
justice is dismissed if the × marks outnumber the rest (Art. 32). Two justices were on the ballot in 2026; 54,153,752 valid ballots.
Junichi Takasu高須順一 · retained
7,664,301 dismiss (14.2%) · 46,489,132 not marked · line at 50%
Mami Okino沖野眞已 · retained
7,436,291 dismiss (13.7%) · 46,717,272 not marked · line at 50%
Chapter VIII · Arts. 92–95 · Local Autonomy Act 地方自治法
Forty-seven prefectures, 1,718 towns and cities.
Local government is presidential, not parliamentary: “The chief executive officers of all local public entities, the
members of their assemblies, and such other local officials as may be determined by law shall be elected by direct
popular vote” (Art. 93(2)).
Prefectures 都道府県
47 · one metropolis, one circuit, two urban prefectures, 43 prefectures
Each elects a governor (知事) and an assembly directly, both for four years (Local Autonomy Act Arts. 93, 140).
Municipalities 市町村
792 cities · 743 towns · 183 villages
Each has an elected mayor and assembly. Mergers cut the number from 3,232 in March 1999 to 1,718 today (MIC).
Two kinds of check
Local Autonomy Act Art. 178
An assembly can pass no confidence in its governor or mayor, who may dissolve the assembly within ten days — a local echo of Article 69.
Special laws
Art. 95
The Diet cannot pass a law that applies to one local entity alone without the consent of a majority of that entity's voters.
Direct demands 直接請求 · signatures of registered voters
Demand
Signatures
Goes to
Law
Make, amend or repeal an ordinance 条例の制定・改廃
1/50 of electors
the governor or mayor, who puts it to the assembly within 20 days
Art. 74
Audit of the administration 事務の監査
1/50
the audit commissioners
Art. 75
Dissolve the assembly 議会の解散
1/3 (less above 400,000)
the election commission; a referendum, majority dissolves
Arts. 76, 78
Recall an assembly member 議員の解職
1/3 of the district's electors (less above 400,000)
the election commission; a referendum
Arts. 80, 83
Recall the governor or mayor 長の解職
1/3 (less above 400,000)
the election commission; a referendum, majority removes
Arts. 81, 83
Try it · Local Autonomy Act 地方自治法 Arts. 74–86
Recall a governor.
Pick a prefecture, or type any number of electors. Signatures must come from registered voters of that place;
a recall or dissolution then goes to a vote of the electors and succeeds with a majority (Arts. 78, 83).
signatures to recall the governor or mayor, or to dissolve the assembly
signatures to demand an ordinance or an audit (1/50)
Recall thresholds: one-third of electors up to 400,000, plus one-sixth of the part from 400,000 to 800,000, plus
one-eighth of the part above 800,000 (Arts. 76, 80, 81). Prefecture elector counts are the lower-house district
registers at the 8 Feb 2026 general election, as a guide.
Chapter IX · Art. 96 · 憲法改正
Never amended.
The Constitution has not been amended since it took effect in 1947. An amendment needs two-thirds of all
members of each house — not just those present — and then a majority of the votes cast in a referendum.
“Amendments to this Constitution shall be initiated by the Diet, through a concurring vote of two-thirds or more of all the members of each House and shall thereupon be submitted to the people for ratification, which shall require the affirmative vote of a majority of all votes cast thereon, at a special referendum or at such election as the Diet shall specify.”
Article 96(1)
House of Representatives · two-thirds of 465 = 310
351 coalition seats · enough
House of Councillors · two-thirds of 248 = 166
120 coalition seats · 46 short
Today's coalition could not initiate an amendment on its own.
Any amendment would need parties beyond the coalition in the upper house, where it holds 120 of 166 needed. Find a two-thirds →
Parties
Who leads the parties.
Liberal Democratic Party · 自由民主党Sanae Takaichi 高市早苗President since 4 Oct 2025
Japan Innovation Party (Ishin) · 日本維新の会Hirofumi Yoshimura 吉村洋文Co-leader Fumitake Fujita; Yoshimura is Governor of Osaka
Democratic Reform Party · 民主改革の会Junya Ogawa 小川淳也Founded 17 Sep 2026 by ex-CDP members of the CRA
Komeito · 公明党Mitsunari Okamoto 岡本三成Since October 2026
Constitutional Democratic Party · 立憲民主党Shunichi Mizuoka 水岡俊一Interim; the CDP now sits mainly in the upper house
Democratic Party for the People · 国民民主党Yuichiro Tamaki 玉木雄一郎
Sanseito · 参政党Sohei Kamiya 神谷宗幣
Team Mirai · チームみらいTakahiro Anno 安野貴博
Japanese Communist Party · 日本共産党Tomoko Tamura 田村智子Chair since Jan 2024
Party of Life (ex-Reiwa) · いのちの党Joji Yamamoto 山本譲司Reiwa Shinsengumi renamed itself on 6 Aug 2026
Conservative Party of Japan · 日本保守党Naoki Hyakuta 百田尚樹
Social Democratic Party · 社会民主党Mizuho Fukushima 福島瑞穂
Party leaders as listed on each party's English Wikipedia page, fetched 4 Nov 2026.
