In 2020, under Shii's leadership, the Japanese Communist Party denounced the Chinese government for its activities in the East China Sea, in the South China Sea, and elsewhere in the Asia-Pacific region. A position paper issued by the party said that China's "great-power chauvinism and hegemonism" were "an adverse current to world peace and progress." At the party's conference in Atami, Shizuoka Prefecture, Shii said that "the Chinese leadership’s mistake is extremely serious. That action does not deserve the name of the Communist Party." The Japanese and Chinese communist parties had previously been diverging for decades.