Tokubei's name is engraved on the epigraph that recognized masons who contributed to the construction of a statue of Emperor Kameyama in Higashi kōen (東公園) in Fukuoka city.

After graduation, Hirota entered the Ministry of Foreign Affairs to become a career diplomat, and he served in a number of overseas posts.

The three principles were the establishment of a Japan–China–Manchukuo bloc, the organization of a Sino-Japanese common front against the spread of communism, and the suppression of anti-Japanese activities within China.

[4] Hirota argued that warlordism and Chinese Communism represented a "festering sore deep down in the bosom of Eastern Asia" that threatened "all Asian races with sure and inescapable death" and considered further military engagement in China to be "heroic surgery," rather than invasion.

[5] In 1936, with the radical factions within the Japanese military discredited after the 26 February incident, Hirota was selected to replace Okada as Prime Minister of Japan.

He resigned after a disagreement with Hisaichi Terauchi, who was serving as the war minister, over a speech by the Rikken Seiyūkai representative Kunimatsu Hamada criticizing military interference in politics.

During his second term as foreign minister, Hirota strongly opposed the military's aggression against China, which completely undermined his efforts to create a Japan-China-Manchukuo alliance against the Soviet Union.

Following Japan's surrender, Hirota was arrested as a Class A war criminal and brought before the International Military Tribunal for the Far East (IMTFE).

Nonetheless, the tribunal condemned Hirota's failure to insist for the Japanese Cabinet act to put an end to the atrocities.