I think the problem is, as people have pointed out, that you need to find a way to avoid the chaos of intervention in China. Post 1933 this is very hard. Already the military was assuming a clear voice within Japanese politics. You need to shake up the situation more generally. So here is my attempt:
Jan 1934 Hirohito suffers a devastating stroke, leaving him debilitated but not dead. A regency council is put in place to help effectively govern Japan during his convalescence.
July 1934 Impatient with the lack of progress, Chiang Kai-Shek launches the Fifth Encirclement Campaign as another all-out assault instead of a slow strangulation of the CCP. KMT forces suffer a major defeat against the communists who launch their own offensive south into Guangdong threatening core economic areas of the Republic and sparking off new waves of Anti-KMT revolts.
Late 1934 Stalin begins to contemplate intervention in China. Increasingly aware of Soviet ambitions, the Japanese army concentrates on building up Manchuria rather than striking into China itself.
Early 1935 Fighting continues in China as Communist insurgents gain ground and former allies abandon Chiang and the KMT. Furthermore Chiang faces increasing pressure from the left-wing of the KMT and other figures to negotiate a settlement with the CCP.
Late 1935 Anti-Communist paranoia running high, Japanese Army launches an undeclared attack on the Soviet East after a series of border-clashes. The resulting Battle of Khalkhyn Temple sees the Japanese force soundly defeated by the Soviets. Kwantung Army officers are humiliated and General Ueda is forced to resign in disgrace.
Early 1936 Emboldened by this military humiliation civilian politicians on the regency council push through elections. Conservative Rikken Seiyukai form a majority.
February 1936 - 2-26 Incident happens as planned but this time the focus of the plotters is on "restoring" Prince Chichibu as head of the government rather than Hirohito himself. The plotters kill a number of ministers and try to seize the Imperial Palace but are defeated as OTL. Prince Chichibu implicates himself in the plot somehow and is forced to resign from the regency council on "heath" grounds. The strain is too much for an ailing Hirohito who dies, leaving his two year old son as Emperor.
1936 - the Civilian Government, emboldened by the resignations in the military triggered by the 2-26 incident and the public belief that the plot somehow killed the sick Hirohito through stress, are able to maneuver more moderate officers into key roles in the army and navy. Officers with suspected ultra-nationalist sympathies are sidelined or blackmarked. In time the 2-26 incident comes to be seen as the moment the political violence in 1930s Japan reached a peak before ebbing away.
1937 - Soviet Union makes increasingly aggressive moves in arming and supporting the CCP, yanking the rug out from under Chiang's feet by withdrawing their support for the KMT. Communists make gains in China and Chiang's fragile coalition begins to fall apart completely. Alarmed by events in China the USA and the UK both make increasingly positive overtures to the Japanese Government, including inviting it to return to the League of Nations in late 1937.
1938-1940s - Japan remains neutral in WWII but, as Chinese Civil War develops and Soviet influence is distracted by events in Europe, acts with British and American blessing to prop up the anti-Communist forces in China.
Ultimately it ends the 20 year period a more stable, if old-fashioned, conservative democracy.