After the
decentralisation movement started, based on the
Omnibus Decentralization Law and an amendment to the Special Law for Municipal Mergers (SLMM) in 1999, which provided strong financial and economic incentives for municipal consolidation, the central government forced municipal mergers by using incentive schemes according to special financial measures: • A grace period was offered to keep an original grant after municipal mergers, combining the grants of the two combined municipalities. If city A received 0, and city B received 100, a merger of A and B would keep 100, guaranteeing the same amount of grants. • After mergers, the issue of special local bonds would be paid through central government grants. These special bonds provided very strong incentive for the implementation of public works to support the new merged municipalities. Although mergers were not mandatory, the central government established a goal of decreasing municipality numbers to 1,000, and used these incentives to urge prefectural governments to promote mergers. There are two types of municipal merger under this and previous policies: • Absorption by one city of others. The core city retains its name, legal status, mayor and legislative body, and municipal offices, while the absorbed entity loses theirs. • The creation of a new entity out of the merger cities. When a new entity is created, they receive new legal status, create a new name and location for government offices, and form a new council.
Local referendums Local governments used local
referendums or questionnaire surveys regarding potential mergers to evaluate
public opinion. 352 local referendums on merging took place from 1999 to 2006.
Great Heisei Amalgamations A vast number of municipal mergers, known as , were executed from 1999 to 2010 (the so-called Great Heisei Amalgamations). Municipality numbers dropped from 3,232 to 1,727 during this period. Due to the , a series of administrative and financial reforms that significantly affected smaller municipalities after their implementation in the early 2000s, many of these small municipalities had to voluntarily merge with others. The main motivation of the reform was stated as to support small local governments that would become unstable in the event of poor fiscal periods. From April 1999 to April 2014, there were 188 cases of municipal absorption, and 461 new municipalities. Among them, 582 consolidations were done during the Great Heisei Consolidations period from April 1999 to March 2006. This number includes duplicated consolidations.
Amalgamate patterns There were 8 merging patterns during the Great Heisei Amalgamations: • Merge established by the Merger Council with original members. • Merge after creating a new Merger Council with new partners. • Merge in another Merger Council after seceding from the original Merger Council. • A merger in which the original Merger Council increased in size with new members. • Continue as independent municipality after seceding from original Merger Council. • Continue as an independent municipality having not joined a Merger Council. • Continue as an independent municipality after the Merger Council dissolves. • Merge on the basis of the Merger Law alone (without a Merger Council).
Record of changes • The
list of mergers and dissolutions of municipalities in Japan shows mergers and dissolutions of municipalities sorted by
prefecture.
Naming of new municipalities Naming a new post-merger municipality is not a negligible matter. Disagreement on a name sometimes causes merger talks to break down. If a city is far larger than the towns joining it, no arguments take place; the city's name simply survives. However, if their sizes do not differ significantly, lengthy disputes can ensue. Sometimes, the problem can be solved by adopting the name of the
district or compounding the names of the localities to be merged; the latter method is relatively common in Europe, but is unusual in Japan. These compounded names are often abbreviated. For example, the
Ōta (大田) ward of Tokyo is a
portmanteau of Ōmori (
大森) and Kamata (蒲
田); Ōkama was not chosen because of its likeness to 'okama', a derogatory word for homosexual.
Toyoshina, Nagano, is an
acronym of the four antecedent villages:
Toba,
Yoshino,
Shinden, and
Nariai. Another common naming method is borrowing a well known nearby place name and adding a direction, such as in
Nishitōkyō ("West Tokyo"),
Kitakyūshū ("North
Kyūshū"),
Higashiōsaka ("East
Osaka"),
Shikokuchūō ("Central
Shikoku") and
Higashiōmi ("East Ōmi"). Other towns sometimes use nouns with pleasant connotations, such as , , or . A characteristic of the Heisei mergers is a rapid increase of
hiragana names. The names of Japan's cities used to be written in
Kanji exclusively. The first instance of "
hiragana municipalities" was , renamed in 1960. The number of place names using hiragana reached 45 by April 2006, including , , , , and , which was upgraded to a
designated city in 2003. The creation of
Minami Alps in 2003 is the first example of a katakana city name. == Criticisms ==