While individual Buddhist, Taoist and Shinto sects have thrived in Japan for centuries, there exists a general underlaying religious consciousness in Japan that is better described as "Japanese Metaphysical Consciousness" and is a spiritual ideology that has existed for centuries in Japan. This spiritual and ethical consciousness can be best defined by the principles of Bushido as it was a conglomeration of all East Asian philosophical and theological schools of thought and more.
This ethical system rooted deeply in Neo-Confucianism, Shinto and Buddhist ideals emphasized loyalty, self-discipline, mastery of martial arts and filial piety. Further influenced by Zen Buddhism introduced to Japan during the Kamakura Shogunate period (1185-1333), Bushido ethics adopted the belief that through human effort people could reach meditative zones of thought beyond the range of verbal expression. The core principle of this system that was adopted by the samurai was that salvation could be attained from within. Originally a loose framework of ideals, Bushido development began in the 10th century and core values were incorporated into the Tokugawa Shogunate (1600-1868) law. It is here where politics (sei) and religion (kyo) became intertwined in every day society.
Shogun Ieyasu Tokugawa issued the “ordinances for the Military Houses,” commanding samurai to train equally in arms and “polite” learning according to the principles of Confucianism. According to Neo-Confucian philosopher Mencius, Righteousness was “a straight and narrow path” to uphold your duties. Through instilling martial valor and perpetuating stories such as the 47 Ronin, the youth and Samurai were instilled with a sense of duty and loyalty to inclined them towards pursuing acts of bravery. Tempered by the ethics of Bushido, while life could be grueling in their training, Samurai would bear the benefits in life and warfare. Stories of valor were used to promote tranquility of mind for Samurai to be able to keep a calm head in the midst of any danger. Through acts of valor and earning respect, Samurai respected each other in warfare to being about a sense of civility to an otherwise pure horror of warfare.
The erosion of traditional Bushido ethics came about during the Meiji Restoration with collapse of the samurai class and the rise of Westernization. The transition between the Edo period and the Meiji period was known as the Bakumatsu period and new religious groups called shinshukyo began to emerge, the most notable being the Tenrikyo, Kurozumikyo and Oomoto. In the new Meiji era, state controlled religion dissipated and bans on religions such as Christianity was lifted, opening up the doors for missionaries and other religious sects to establish a foothold in Japan for the first time in centuries.
This new acceptance was short lived however under the Imperial Japanese government in the 1930s and 1940s, reestablishing state Shintoism as the official religion of Japan and suppressed any religion they believed to undermine its authority. As such, many traditional ethics of Bushido saw a revitalization during Japan's Imperialistic efforts, however had been warped by political agendas. These ideals were corrupted by the Imperial government who incorporated these ideals into their government political manifesto titled the Kokutai no Hongi to manipulate ethics to blindly follow the emperor and ignored many of the benevolent aspects. As such, upon the fall of the Axis powers, the Japanese government was politically restructured and as such, many of their ideologies were subverted for Western ideals with periodic revitalization.
The Japanese philosophical and spiritual mindset when not adapted as a political system is one of peace and inner strength that is present in the original precepts of Bushido, as laid out by Dr. Nitobe Inazo, pre-World War II. Inazo also condemned the Imperial actions of pre-World War II Japan stating that their ideals did not coincide with the true precepts of Bushido.