Actually, it is more nuanced than that. There is an ongoing debate. Here is a quote:
The issue of the Emperor’s responsibility for war crimes
Many historians see Emperor Shōwa as responsible for the atrocities committed by the imperial forces in the Second Sino-Japanese War and in World War II and feel that he, some members of the imperial family such as his brother Prince Chichibu, his cousins Prince Takeda and Prince Fushimi, and his uncles Prince Kan’in, Prince Asaka, and Prince Higashikuni, should have been tried for war crimes.[29][30]. Because of this perception of responsibility for war crimes and lack of accountability, many Asians[who?] residing in countries that were subject to Japanese invasion, as well as others in nations that fought Japan, retain a hostile attitude towards the Japanese imperial family.[citation needed]
The issue of Hirohito’s responsibility for war crimes is a debate regarding how much real control the Emperor had over the Japanese military during the two wars. Officially, the imperial constitution, adopted under Emperor Meiji, gave full power to the Emperor. Article 4 prescribed that, “The Emperor is the head of the Empire, combining in Himself the rights of sovereignty, and exercises them, according to the provisions of the present Constitution,” while, according to article 6, “The Emperor gives sanction to laws and orders them to be promulgated and executed,” and article 11, “The Emperor has the supreme command of the Army and the Navy.” The Emperor was thus the leader of the Imperial General Headquarters.[31]
In 1971, David Bergamini showed how primary sources, such as the “Sugiyama memo” and the diaries of Kido and Konoe, describe in detail the informal meetings Emperor Shōwa had with his chiefs of staff and ministers. Bergamini concluded that the Emperor was kept informed of all main military operations and that he frequently questioned his senior staff and asked for changes.[32]
Historians such as Herbert Bix, Akira Fujiwara, Peter Wetzler, and Akira Yamada assert that the post-war view focusing on imperial conferences misses the importance of numerous “behind the chrysanthemum curtain” meetings where the real decisions were made between the emperor, his chiefs of staff, and the cabinet. Historians such as Fujiwara [33] and Wetzler [34], based on the primary sources and the monumental work of Shirō Hara,[35] have produced evidence suggesting that the Emperor worked through intermediaries to exercise a great deal of control over the military and was neither bellicose nor a pacifist, but an opportunist who governed in a pluralistic decision-making process. American historian Herbert Bix argues that Emperor Shōwa might have been the prime mover of most of the events of the two wars.[36]
The view promoted by both the Japanese Imperial Palace and the American occupation forces immediately after World War II had Emperor Shōwa as a powerless figurehead behaving strictly according to protocol, while remaining at a distance from the decision-making processes. This view was endorsed by Prime Minister Noboru Takeshita in a speech on the day of Hirohito’s death, in which Takeshita asserted that the war had broken out against [Hirohito’s] wishes. Takeshita’s statement provoked outrage in nations in East Asia and Commonwealth nations such as the United Kingdom, Australia, New Zealand and Canada.[37] For Fujiwara, however, “the thesis that the Emperor, as an organ of responsibility, could not reverse cabinet decision, is a myth fabricated after the war.” [38]
In Japan, debate over the Emperor’s responsibility was taboo while he was still alive. After his death, however, debate began to surface over the extent of his involvement and thus his culpability.[37]
In the years immediately after Hirohito’s death, the debate in Japan was fierce. Susan Chira reported that, “Scholars who have spoken out against the late Emperor have received threatening phone calls from Japan’s extremist right wing.”[37] One example of actual violence occurred in 1990 when the mayor of Nagasaki, Hitoshi Motoshima, was shot and critically wounded by a member of the ultranationalist group, Seikijuku; Motoshima managed to recover from the attack. In 1989, Motoshima had broken what was characterized as “one of [Japan’s] most sensitive taboos” by asserting that Emperor Hirohito bore some responsibility for World War II.[39]
Kentaro Awaya argues that post-war Japanese public opinion supporting protection of the Emperor was influenced by US propaganda promoting the view that the Emperor together with the Japanese people had been fooled by the military.
Here is the source