February 20 – 1928 Japanese general election: The first general election after the introduction of universal male suffrage was passed in 1925. The ruling Rikken Seiyūkai led by Prime Minister Tanaka Giichi won one more seat than the opposition Rikken Minseitō led by Hamaguchi Osachi, although Rikken Minseitō had received slightly more votes. The hung parliament led to the Tanaka government continuing in office.
March 15 – March 15 incident: Alarmed by gains made by socialists and communists in the 1928 general election, the conservative government of Prime Minister Giichi Tanaka ordered the mass arrest of known communists and socialists and suspected communist and socialist sympathizers. The arrests occurred throughout Japan, and a total of 1652 people were apprehended.[2]
June 4 – Huanggutun Incident: Chinese warlord Zhang Zuolin is killed by low-ranking officer in the Japanese Kwantung Army when a bomb his personal train is travelling over explodes. Emperor Hirohito harshly criticized the event and eventually dismissed Prime Minister Tanaka Giichi for his inability to arrest and prosecute the plotters of the incident.[8]
July 28–August 12 – Japan competes in the ninth Summer Olympics held in Amsterdam, Netherlands. For the 1928 Olympics, Japan won 2 golds, 2 silvers and 1 bronze.
^Ji'nan Government (September 1, 2005). "The Year of 1928". Archived from the original on July 24, 2012. Retrieved August 16, 2013. 蔡公时用日语抗议,日兵竟将其耳鼻割去,继又挖去舌头、眼睛。日军将被缚人员的衣服剥光,恣意鞭打,然后拉至院内用机枪扫射
^Jay Taylor, The Generalissimo: Chiang Kai-Shek and the Struggle for Modern China (Cambridge, MA: Belknap Press of Harvard University Press, 2009), 82-83.
^Bix. Hirohito and the Making of Modern Japan. pages 216-218 Zhang was a de jure head of state because he held absolute power over the internationally recognized Beiyang government based in Beijing.