The common theory of the constitution study group is that the current system under the Constitution of Japan is not considered as the constitutional monarchy and therefore the Emperor is not the head of state; but there are some theories that believe the Emperor is practically the head of state.
憲法学会の学説では、日本国憲法下の現行体制を立憲君主制とは捉えず、また天皇は元首ではないとするのが通説であるが、実質的に元首であるという見解を示す説もある。