Q: What is the constitutional status of the National Diet in Japan, and how is it organized (bicameralism, sessions)?

The National Diet (国会 - Kokkai) is the central institution of Japan's representative democracy, holding a uniquely prominent position within the nation's constitutional framework. Understanding its constitutional status and organizational structure, particularly its bicameral nature and session-based operation, is essential for comprehending the legislative process and the balance of power in Japanese governance. This article explores these foundational aspects of the Diet.

The Constitutional Status of the National Diet

The Constitution of Japan bestows upon the Diet a distinctive and paramount status through several key provisions:

1. Representative of All the People (全国民を代表する選挙された議員 - Zenkoku Min o Daihyō Suru Senkyo Sareta Giin):
   Article 43, paragraph 1, stipulates that "Both Houses shall consist of elected members, representative of all the people." This establishes the Diet as the embodiment of popular sovereignty, with its members deriving their mandate directly from the electorate. The concept of "representative of all the people" signifies that Diet members are not mere delegates bound by the specific interests of their constituencies or any particular group. Instead, they are expected to deliberate and act in the interest of the nation as a whole. This principle supports the idea of "free mandate" (jiyūinin - 自由委任), where representatives are guided by their conscience and judgment, rather than by binding instructions from their electors, contrasting with the "imperative mandate" (meireiinin - 命令委任) seen in some historical systems.
2. The Highest Organ of State Power (国権の最高機関 - Kokken no Saikō Kikan):
   Article 41 declares the Diet to be "the highest organ of state power." The precise legal meaning of this phrase has been a subject of considerable academic debate.
   • One interpretation, the "Political Beauty Theory" (Seijiteki Bishō Setsu - 政治的美称説), which is considered the prevailing view, suggests that this designation is primarily a political or symbolic honorific, emphasizing the Diet's closeness to the sovereign people as their directly elected representatives, rather than granting it legal superiority over the other branches of government (the Cabinet and the Judiciary). This view is cautious about deriving concrete legal powers for the Diet over other branches solely from this phrase, as that could contradict the principle of separation of powers.
   • An alternative view, the "Unified Control Organ Theory" (Tōkatsu Kikan Setsu - 統括機関説), argues that this phrase imbues the Diet with a comprehensive authority to coordinate and ultimately direct national governance. However, this interpretation has been criticized for potentially undermining the independence of the executive and judicial branches.
   • Other theories, such as the "Comprehensive Coordinating Function Theory" (Sōgō Chōsei Kinō Setsu - 総合調整機能説) or the "Highest Locus of Responsibility Theory" (Saikō Sekinin Chii Setsu - 最高責任地位説), attempt to find a middle ground, suggesting that the Diet has a central role in coordinating state functions or bears ultimate political responsibility for governance, without necessarily implying direct legal command over other branches in all matters.
     Regardless of the precise interpretation, this status underscores the Diet's central role in a democratic system founded on popular sovereignty.
3. The Sole Law-Making Organ (唯一の立法機関 - Yuiitsu no Rippō Kikan):
   Article 41 also designates the Diet as "the sole law-making organ of the State." This has two primary implications:
   • Principle of Diet-Centered Legislation (Kokkai Chūshin Rippō no Gensoku - 国会中心立法の原則): All formal laws (statutes - hōritsu) must be enacted by the Diet. Executive agencies cannot create laws independently, though they can issue cabinet orders or ministerial ordinances to implement laws, provided there is statutory authorization (delegated legislation). Emergency decrees or independent executive orders with the force of law, which existed under the Meiji Constitution, are not permitted under the current Constitution. Exceptions to this principle are explicitly provided in the Constitution itself, such as the rule-making power of each House of the Diet (Article 58, paragraph 2) and the Supreme Court (Article 77).
   • Principle of Diet Monopolization of Legislation (Kokkai Tandoku Rippō no Gensoku - 国会単独立法の原則): The Diet can enact laws without the involvement or approval of any other state organ. This contrasts with the Meiji Constitution, where the Emperor's sanction was required for laws to take effect. While laws are promulgated by the Emperor (Article 7, item 1), and countersigned by the Prime Minister and relevant Ministers of State (Article 74), these are formal acts and not conditions for the law's enactment, which is complete upon passage by both Houses (or by the House of Representatives under its override provisions). An exception to this principle is found in Article 95, which requires a local referendum for special laws applicable only to a single local public entity. The Cabinet's extensive role in practice in submitting bills to the Diet is generally seen as compatible with this principle, as the final decision-making power rests with the Diet.

The Organizational Structure of the National Diet

The Constitution and the Diet Law lay out the fundamental organizational framework of the Diet.

1. Bicameralism (二院制 - Niinsei)

Article 42 states, "The Diet shall consist of two Houses, namely the House of Representatives and the House of Councillors." Japan thus adopts a bicameral system. The rationale for bicameralism in Japan, where both houses are comprised of "elected members, representative of all the people" (Article 43), differs from systems where the upper house might represent specific territorial units (as in federal states) or historical aristocratic interests.

The generally cited purposes of bicameralism in the Japanese context include:

• Prudent Deliberation: Allowing for more careful and thorough examination of legislation by having it pass through two distinct chambers.
• Representation of Diverse Perspectives: Potentially reflecting a broader range of public opinion than a unicameral system might.
• Mutual Checks and Balances: One House can check the potential excesses or errors of the other.
• Ensuring Continuity of Legislative Function: The House of Councillors is not subject to dissolution like the House of Representatives, and it can meet in emergency session when the House of Representatives is dissolved (Article 54, paragraph 2).

Despite these theoretical benefits, the actual functioning of Japan's bicameral system has faced challenges. If both Houses are controlled by the same party or coalition, the House of Councillors may be perceived as a "rubber stamp" for the House of Representatives. Conversely, when different parties or coalitions control the two Houses (a "twisted Diet" or nejire Kokkai - ねじれ国会), legislative gridlock can occur, leading to criticisms that the House of Councillors is "too powerful."

The Constitution establishes a general principle of independent activity for each House (dokuritsu katsudō no gensoku - 独立活動の原則), meaning they deliberate and vote separately. However, it also establishes the primacy of the House of Representatives in several key areas to prevent legislative paralysis:

• Budget: The budget must be submitted to the House of Representatives first (Article 60). If the House of Councillors makes a different decision from the House of Representatives and no agreement can be reached through a joint committee, or if the House of Councillors fails to take final action within 30 days, the decision of the House of Representatives becomes the decision of the Diet.
• Treaties: Similar rules apply to the approval of treaties (Article 61).
• Designation of the Prime Minister: The decision of the House of Representatives prevails if the two Houses disagree and cannot reconcile, or if the House of Councillors fails to make a designation within 10 days (Article 67).
• Legislation: For ordinary laws, if the House of Councillors rejects or amends a bill passed by the House of Representatives, the bill can still become law if the House of Representatives re-passes it by a two-thirds majority of the members present (Article 59, paragraph 2).

A joint committee of both Houses (ryōin kyōgikai - 両院協議会) can be established to resolve disagreements on bills, the budget, treaties, and the designation of the Prime Minister, but its decisions are not binding unless adopted by each House (or unless the House of Representatives' overriding power comes into play).

2. Term System (任期制 - Ninkisei)

Diet members are elected for fixed terms, providing a temporal limit on their exercise of power and ensuring periodic accountability to the electorate.

• House of Representatives: Members have a four-year term. However, the term terminates before its full expiration if the House of Representatives is dissolved (Article 45). Dissolution makes the lower house more immediately responsive to shifts in public opinion.
• House of Councillors: Members have a six-year term, and elections for one-half of its members are held every three years (Article 46). The House of Councillors cannot be dissolved. This staggered election cycle and lack of dissolution are intended to provide greater stability and a longer-term perspective to the legislative process, contrasting with the more politically volatile lower house.

3. Session System (会期制 - Kaiki-sei)

The Diet does not operate continuously throughout the year but conducts its business within defined periods called "sessions" (kaiki - 会期). The convocation of the Diet is formally an act of the Emperor with the advice and approval of the Cabinet (Article 7, item 2), but the substantive decision to convene rests with the Cabinet. There are three types of sessions:

• Ordinary Session (Jōkai - 常会): Must be convoked once per year (Article 52). The Diet Law specifies that it should typically be convened in January and last for 150 days (Diet Law, Arts. 2, 10). It can be extended once by a resolution of both Houses (or by the House of Representatives if they disagree) (Diet Law, Art. 12). This session is primarily for deliberating the annual budget and other general legislative matters.
• Extraordinary Session (Rinjikai - 臨時会): Can be convened by the Cabinet as deemed necessary (Article 53). The Cabinet must convene an extraordinary session when a quarter or more of the total members of either House makes the demand. While the timing of convocation following such a demand is at the Cabinet's discretion, it is understood that it must be within a reasonable period. These sessions deal with urgent matters or unfinished business.
• Special Session (Tokubetsukai - 特別会): Must be convoked within 30 days from the date of a general election of the House of Representatives (following dissolution or term expiration) (Article 54, paragraph 1). Its primary purpose is to designate a new Prime Minister. The Diet Law also provides for the convocation of an extraordinary session within 30 days of the start of the term of House of Councillors members following their regular election (Diet Law, Art. 2-3).

A significant feature linked to the session system is the Principle of Non-Continuation of Sessions (Kaiki Fukkeizoku no Gensoku - 会期不継続の原則), also known as the principle of discontinuity of Diet business. This means that, as a general rule, any bill or matter not decided upon by the end of a session is dropped and does not automatically carry over to the next session (Diet Law, Art. 68). This principle, inherited from pre-war practice, can lead to inefficiencies, as bills often need to be reintroduced and re-deliberated. However, the Diet Law allows for exceptions, such as permitting committees to continue examining specific matters during recess with the approval of their respective Houses, and allowing such matters to be carried over (Diet Law, Arts. 47(2), 68 proviso). This has somewhat mitigated the strictness of the non-continuation principle.

Another related principle is the Rule Against Double Jeopardy in the Same Session (Ichiji Fusai-gi no Gensoku - 一事不再議の原則), which generally prohibits a bill or motion, once defeated, from being brought up again for deliberation in the same session. While not explicitly in the current Constitution (unlike the Meiji Constitution), it is a widely accepted parliamentary norm aimed at efficient proceedings, though it is not applied so rigidly as to prevent reconsideration if circumstances significantly change.

4. Meeting Structure: Plenary Sessions and Committees

• Plenary Sessions (Honkaigi - 本会議): These are meetings of the entire membership of a House and are the formal arenas for final votes on bills and other important decisions.
• Committees (Iinkai - 委員会): Due to the volume and complexity of legislative work, much of the detailed deliberation, scrutiny, and amendment of bills occurs in committees (both standing and special). This has led to a "committee-centric" system (iinkai chūshin shugi - 委員会中心主義), where committees play a powerful role in shaping legislation before it reaches the plenary session.
• Quorum and Voting: For ordinary business, each House cannot open proceedings or make decisions unless at least one-third of its total members are present (Article 56, paragraph 1). Decisions are made by a majority of those present, except as otherwise provided in the Constitution (e.g., the two-thirds majority for expelling a member or overriding the House of Councillors). In case of a tie, the presiding officer casts the deciding vote (Article 56, paragraph 2). "Total members" for quorum purposes is usually interpreted as the legally fixed number of seats.
• Public Sessions: Deliberations in both Houses must be public (Article 57, paragraph 1). However, a secret session may be held if decided by a majority of two-thirds or more of those members present. The minutes of public sessions must be published and given general circulation, except for those parts of secret session minutes deemed to require secrecy (Article 57, paragraphs 2 and 3). While this public access principle primarily applies to plenary sessions, committee meetings are also largely open to the public and media in practice, though House rules can allow for closed committee sessions.

Conclusion: A Diet Defined by Representation, Supremacy in Law-Making, and Inter-Branch Dynamics

The National Diet of Japan is constitutionally positioned as the preeminent organ of state power, directly representing the sovereign people and holding the exclusive authority to make laws. Its bicameral structure, while intended to promote prudence and diverse representation, operates under rules that ultimately ensure the primacy of the more popularly responsive House of Representatives. The session-based system, with its distinct types of convocations and traditional procedural principles, provides the framework for the Diet's annual legislative and oversight cycle. These organizational features are not merely technical details but are integral to how the Diet fulfills its multifaceted constitutional mandate.