Japan Revolutionary Communist League (Revolutionary Marxist Faction)

The Japan Revolutionary Communist League (Revolutionary Marxist Faction) (Japanese: 日本革命的共産主義者同盟革命的マルクス主義派 Nihon Kakumeiteki Kyōsansugisha Dōmei, Kakumeiteki Marukusu Shugiha) is a Japanese Communist revolutionary group, often referred to as Kakumaru-ha. It is classified as a violent organization. The Japanese Communist Party refers to it as a "fake 'left-wing' violent organization".

The group's origins lie in its split from the Japanese Communist Party following the Hungarian Revolution of 1956. The dissenting factions attended a congress of the Japanese New Left in 1957 and agreed to unite as the Japan Revolutionary Communist League. In 1959, the party split, with dissidents including Kuroda Kan'ichi forming the Japan Revolutionary Communist League National Committee.

The National Committee itself split in 1963. The majority became known as the Japan Revolutionary Communist League, National Committee (Middle Core Faction), while the minority around Kuroda Kan'ichi formed the "Revolutionary Marxist Faction". The two groups had frequent violent conflicts and, by the mid-1970s, these were resulting in several deaths per year – 16 in 1975 alone. The organisation subsequently engaged in a number of high-profile guerrilla activities while continuing to organise on university campuses, primarily through their Zengakuren faction. In 1998, police seized thousands of recordings of their conversations made by Faction members, which a spokesperson claimed had been "necessary to protect the organisation".

Formerly close to the Spartacist League, the group now has friendly relations with the International Trotskyist Fraction.