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 as cultural institutions. A study about the reason for the growth in lay believers and increased engagement in society attributes the cause to Nichiren teachings of 'social responsibility': "In the tradition of Nichiren Buddhism, however, we find the Lotus Sutra linked to a view of social responsibility that is distinctive". According to an academic study, lay believers of Buddhism "...offer an alternative view of Japan where their form of Buddhism would form the religious foundation of a peaceful and psychologically and materially enriched society". ["East Asian Buddhism is very diverse in its teachings and monastic practices, and Japanese Buddhism, in