Buddhism in Japan began teaching devotion to the "Lotus Sutra". Eventually, his disciples formed their own school of Nichiren Buddhism, which includes various sects that have their own interpretations of Nichiren's teachings. Nichiren Buddhism established the foundation of Japanese Buddhism in the thirteenth century. The school is known for its sociopolitical activism and looks to reform society through faith. In the Muromachi period, Zen, particularly the Rinzai school, obtained the help of the Ashikaga shogunate and the Emperor of Japan, and accomplished considerable development. After the Sengoku period of war, Japan was re-united in the Azuchi–Momoyama period. This decreased the power of Buddhism,
Buddhism in Japan of the sixth century. 816: Kūkai founds . One of the major schools of Buddhism in Japan today and one of the few surviving Vajrayana lineages in East Asia, it originally spread from India to China through traveling monks such as Vajrabodhi and Amoghavajra. Known in Chinese as the Tangmi, these esoteric teachings would flourish in Japan under the auspices of a Buddhist monk named , who traveled to Tang China in 804 as part of the same expedition as Saichō. In the capital he studied Tangmi and Sanskrit and received initiation from Huiguo. On returning to Japan, Kūkai eventually