Kurokawa Cup: prank and protest against immunity of top Japanese prosecutor Favorite 

Kurokawa Cup is a protest against former head Tokyo prosecutor Hiromu Kurokawa's de facto immunity after he had played mahjong for money, which is an illegal act in Japan.

After a weekly magazine reported that Kurokawa played mahjong for money with journalists when Japan was under a novel coronavirus state of emergency, a group of protestors set up a table on the sidewalk in front of the Public Prosecutor's Office in Tokyo in order to hold a mahjong tournament, dubbed the Kurokawa Cup. The Japanese Justice Ministry explained that while betting on mahjong is illegal, the rate Kurokawa and the journalists applied to their games is not deemed too high in light of common sense and therefore . Participants in the first Kurokawa Cup applied the same "Kurokawa rate," making a mock of the incident and pointing that Kurokawa was given a special treatment despite the illegal act because of his close relation to former Prime Minister Shinzo Abe.

In questioning by the Tokyo District Public Prosecutors Office, Kurokawa has admitted gambling on mahjong with three employees of the Asahi Shimbun and the Sankei Shimbun, both major Japanese dailies. Public prosecutors have decided not to indict Kurokawa.

Kurokawa’s close relationship with the administration of former Prime Minister Shinzo Abe had also come under scrutiny amid the scandal, contributing to the Abe Cabinet’s sagging approval rating.