1927 During the Spring Festival, Liu Fei returned to his hometown. The local villagers were deeply proud of his achievements and held a welcome meeting. Liu Fei delivered a speech at the meeting to publicize Sun Yat-sen's idea that the national revolution must rely on workers and peasants. After the Spring Festival, Liu Fei left his hometown for Shanghai, attended a short-term Japanese class, and soon arrived in Japan by boat from Shanghai. He studied Japanese for three months in Tokyo, Japan, and was introduced to the 57th Wing of the 1 Division in Shiori Sakura-CHO, Chiba Prefecture near Tokyo. He was trained for half a year and was admitted to the Japanese Army Infantry School after passing the examination.
In the Army Step School, Liu Fei continued to learn Japanese besides studying military theory and taking part in training. In less than two years, he translated the Japanese book "Battle Outline". Based on his own study and research, he wrote a pamphlet "On Saving the Nation by War" and brought it back to China. 1930, Liu Fei graduated from the Army Infantry Academy, and was sent to the Army University for further study for four years without test because of his excellent performance.
While studying in Japan, Liu Fei paid close attention to the domestic situation in Japan. He took a clear-cut stand against the counter-revolutionary actions of Chiang Kai-shek and the Kuomintang Rightists in the "April 12th" coup, and resolutely opposed Chiang Kai-shek's reactionary policy of "being busy outside must be determined internally". He took an active part in gatherings organized by progressive Japanese students in China, such as Ji 'nan Massacre Memorial Day, May 4th Movement and Double Ten. After the "September 18th Incident" and "November 28th Incident" when Japanese imperialism invaded China, he participated in anti-Japanese patriotic activities organized by Japanese students studying in China, sent representatives back to China with other students, and petitioned the Nanjing government to stop the civil war and declare war on Japan. In addition, he also helped some Japanese students studying in China and patriots with difficulties.
Liu Fei often talks with his good friend Chen Duan and others about how to enrich Qiang Bing. He said that continuing to study military affairs in Japan is to prepare for China's future war against Japan, that is, "using children's spears as a shield for attack". He believes that China and Japan will eventually go to war. China can survive only by resolutely resisting Japan; China society can only wash away the dirt through War of Resistance against Japanese Aggression; China's national spirit can only be developed through War of Resistance against Japanese Aggression. His foresight and judgment have been proved by history.
Liu Fei wisely chose to study in Japan for seven years, avoiding attending the Qing Dynasty, such as Chiang Kai-shek's counter-revolution, the split between Nanjing and Han, the Tang Dynasty's Western Expedition, the battle between Jiang Feng and Jiang, and the five "encirclement and suppression" campaigns of Jiangxi Red Army. This made him "very happy to remain innocent all his life."
Although they are closely related to Bai Chongxi, they have their own opinions on key issues, from "finding their own way out" to "parting ways" with Belarus. Cheng Siyuan said: "He has changed from a man who has always been called an unruly person to a book cutter, which shows that he is resilient and unattainable.".