During Puyi's visit to Japan, Japan only used a grand welcoming ceremony to show the outside world that Puyi was not his puppet, so as to witness the friendly development of the two countries.
Extended data:
In the 23rd year of the Republic of China (the third year of Datong, 1934), Puyi took office in Manchukuo on February 18, and the founding year was "Datong". On March 6th, under the close surveillance of Japanese spies, Puyi, the deposed emperor of the Qing Dynasty, secretly came to "Tanggangzi Hot Spring" and signed the "Tanggangzi Hot Spring Secret Agreement" with the representative of the commander of the Kwantung Army. Secret agreements mainly include:
First, the maintenance of public security and national defense in Manchukuo was entrusted to the Japanese army.
Second, the management and construction of railways, harbors, waterways and air routes necessary for national defense are entrusted to Japan.
Third, the Senate of Manchukuo should appoint Japanese, and the central and local government organs should also appoint Japanese. Their appointment and removal need the consent of the commander of Kwantung Army.
Four, the above purposes and provisions are the basis for the two countries to conclude a formal treaty in the future.
In the thirty-fifth year of the Republic of China (1946), Puyi went to Japan under the escort of the Soviet Union. Puyi stated in court how she was watched by Japanese imperialists and had no rights or even personal freedom.
Baidu Encyclopedia-Puyi
The secret agreement signed by People's Daily Online-Puyi: Transfer Manchukuo to the Japanese?