was a Japanese Buddhist monk who introduced the concept of Zen

Zen

Zen is a school of Mahāyāna Buddhism founded by the Buddhist monk Bodhidharma. The word Zen is from the Japanese pronunciation of the Chinese word Chán , which in turn is derived from the Sanskrit word dhyāna, which can be approximately translated as "meditation" or "meditative state."Zen...

 to Japan. He did not receive any formal dharma transmission

Dharma transmission

Dharma transmission refers to "the manner in which the teaching, or Dharma, is passed from a Zen master to their disciple and heir...

, but invented his own teachings, which he called the "Japan Bodhidharma

Bodhidharma

Bodhidharma was a Buddhist monk who lived during the 5th/6th century AD. He is traditionally credited as the transmitter of Ch'an to China, and regarded as the first Chinese patriarch...

 School", or Darumashū. Later, he dispatched one of his disciples to China to receive a letter of approval from Zhuóān Déguāng (拙庵德光, 1121–1203). His school was quickly eclipsed and did not influence either of major schools of Zen, Rinzai and Sōtō

Soto

Sōtō Zen , or is, with Rinzai and Ōbaku, one of the three most populous sects of Zen in Japanese Buddhism.The Sōtō sect was first established as the Caodong sect during the Tang Dynasty in China by Dongshan Liangjie in the 9th century, which Dōgen Zenji then brought to Japan in the 13th century...

, which later arrived in Japan via more traditional means, but his unorthodox teaching was later brought up in Nichiren

Nichiren

Nichiren was a Buddhist monk who lived during the Kamakura period in Japan. Nichiren taught devotion to the Lotus Sutra, entitled Myōhō-Renge-Kyō in Japanese, as the exclusive means to attain enlightenment and the chanting of Nam-Myōhō-Renge-Kyō as the essential practice of the teaching...

's writings in order to criticize it and, by extension, Zen generally.