Contemporary specialists in comparative constitutional law are paying increasing attention to the phenomena of "authoritarian constitutionalism", "abusive constitutionalism" or "stealth constitutionalism". The term "abusive constitutionalism", which at first sight appears to be acontradictio in adjecto, should be understood as describing the phenomenon whereby, in countries where a liberal democratic regime has been established and has functioned relatively well for some time, an authoritarian regime has been established, while maintaining a constitutionalist regime, or even when some symptoms of such a situation have emerged because of populist leadership. We consider that the phenomenon of authoritarian drift of constitutionalism occurs in a situation where control and criticism of political power by the media, legal control of government activities by the judiciary, as well as a change of government are less and less possible. This situation is the result of a policy based on a populist leadership, whether that leadership is supported by the right or the left, even though the constitutionalist regime is not disrupted by illegal or violent means such as a military coup d'État. This article aims to study the authoritarianism of contemporary Japanese politics under Shinzo Abe's government from 2012 to today, from the perspective of a constitutionalist. We believe that analysing the case of Japan is worthwhile, as it will allow us to judge whether Japan can be considered as a country that tends to become a "competitive authoritarian regime" of a liberal democracy. For this reason, the purpose of this study is to identify how such an authoritarian phenomenon of Japanese constitutionalism could have developed under the current Abe government, and to what extent.