Short answers, pulled from the story.
The January 28 incident was an armed conflict between the Republic of China and the Empire of Japan that lasted from the 28th of January to the 3rd of March 1932, fought across the districts of Shanghai. It is regarded as the first modern war waged in a large city between two heavily equipped armies.
On the 18th of January 1932, five Japanese Nichiren Buddhist monks were beaten by Chinese civilians near Shanghai's Sanyou Factory; one monk died and two were seriously injured. A Japanese group retaliated by burning the factory, killing two Chinese workers, and the incident escalated into full-scale fighting.
Yes. Major Tanaka Ryukichi of the Kwantung Army later admitted, at the International Military Tribunal for the Far East and in his postwar memoirs, that he had paid Chinese civilians to beat the Buddhist monks in order to create a pretext for Japanese naval intervention in Shanghai and divert international attention from Japanese operations in Manchuria.
The Shanghai Ceasefire Agreement made Shanghai a demilitarized zone and prohibited China from stationing troops in areas surrounding Shanghai, Suzhou, and Kunshan. China was permitted to maintain only a small police force within the city, while Japan was allowed to keep a limited military presence.
The incident helped undermine civilian rule in Tokyo. Prime Minister Inukai Tsuyoshi was assassinated on the 15th of May 1932.
Yoon Bong-Gil was a Korean nationalist who severely wounded Yoshinori Shirakawa, the commander of the Shanghai Expeditionary Army, at a birthday celebration for Emperor Hirohito held at Shanghai's Hongkou Park. Shirakawa died of his injuries on the 26th of May 1932.