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,
Reality in Buddhism of interdependent origination. One of the most discussed themes in Buddhism is that of the emptiness ("sunyata") of form (Pali: "rūpa"), an important corollary of the transient and conditioned nature of phenomena. Reality is seen, ultimately, in Buddhism as a form of 'projection', resulting from the fruition ("vipaka") of karmic seeds ("sankharas"). The precise nature of this 'illusion' that is the phenomenal universe is debated among different schools. For example; Buddhist sutras devote considerable space to the concept of reality, with each of two major doctrines—the Doctrine of Dependent Origination ("pratitya-samutpada") and the Doctrine of Cause and Effect ("karma" and