Can you clarify what you mean? All of these were at various times imported and hence, at those times were treated as foreign ideas. Buddhists first arrived in Japan through China and Korea and initial uptake was quite slow. I believe the term “Shinto” only is coined in this period to differentiate Buddhism and native religious practices.
More than a millennium later, in the nationalist Meiji Restoration period (1868–1912), there was a concerted attempt to stamp out or at least marginalize Buddhism specifically because the modernists who came to power saw it as foreign. The campaign they led against Buddhism, Haibutsu kishaku, was not subtle to say the least as it first sought to separate Shinto and Buddhism (they had both theologically and organizationally become very intertwined over the centuries, with Shinto shrines overseeing Buddhist temples and vice verse) and then “abolish Buddhism”. Do you mean the Indian origin of Buddhism specifically, or are you asking about something else? Obviously, many people see Christianity as the native and dominant belief of Europe and the United States while still recognizing that Jesus was born and died in Roman Palestine and that the earliest adherents outside of Judea were in Greece and Asia Minor. Is that what it means to have a foreign origin? Or is something else?
So, others have already commented on the fact that Buddhism was always regarded by East Asian cultures as foreign, but this isn't precisely true, at least not entirely. Furthermore, it skirts around the fascinating history of attempts to both nativise Buddhism in China and also to link native developments back to India. To understand this, we must first look at the early history of Buddhism in China.
Buddhism first appeared in China around the first or second century CE from Kushan, Sogdian, and Khotanese monks and traders along the Silk Road. The earliest mention of Buddhism in the Chinese annals comes from the biography of Prince Ying during the late first century which mentions a cousin of the Prince having dedicated a feast to the Buddha and Lao Tzu, as well as the Emperor. Quote: "Ying expressed repentence for his former deeds and then used the ransom money to prepare a sumptuous feast for the pious laymen and monks living in his kingdom."^1
But Buddhism did not appear in China unaltered, nor was it entirely accepted at first. The transmission of Buddhism along the Silk Road fused it with some other beliefs. It is uncertain as to exactly the form that this early Chinese Buddhism took, but scholars believe it to have been Dharmaguptaka or Sarvāstivāda and there is a possibility of some Iranian influence on it. What is very clear though, is that in our early documents on Buddhism in China, there is a distinct lack of that most distinctive doctrine of Buddhism (Jonang and Dhammakaya notwithstanding): no self. In fact, it appears that Buddhism used a Daoist and Confucian framework to present itself to the Han. Karma and Rebirth are the core tenets, but equally important was the idea of the indestructibility of the soul. This, of course, came from earlier Confucian and Daoist beliefs, and showed how the two were mixed and competing.^2 To the Chinese "Buddhism was but another form of Daoism".^3
Buddhism and Daoism borrowed (some might say plagirized) from each other's texts liberally. While the Daoists initially adopted the sutra literature from the Buddhists, the Buddhists were notorious for copying Daoist sutras and claiming them to be authentically Buddhist, whether or not that is true, certainly they borrowed significantly from one another.^4
Of course, faced with the threat of a competing religion, the Daoists began to claim that Buddhism wasn't so foreign after all, but was the teaching of Laozi to the "barbarians". In the fourth century two texts emerged claiming that Buddhism was the corrupt form of Daoism misunderstood by the "barbarians": the Hua Hu Jing (Education of the Barbarians) and the Santian Neiji Jing (Sutra on the Inner Explanations of the Three Heavens). These texts were both put forth as the teachings of Laozi and that the Buddha was in fact, Laozi. ^4
The Hua Hu Jing is mainly a text detailing doctrine and purports to be the way that Laozi taught barbarians. Throughout the piece there are a number of veiled attacks on Buddhist doctrines--especially non-self, impermanence, and celibacy-- showing how Buddhism was inferior to Daoism. Crucial to this piece is the introduction of Partial Religions. The piece partial religions like so:
There are many partial religions, and then there is the Integral Way. Partial religions are desperate, clever, human inventions; the Integral Way is a deep expression of the pure, whole universal mind. Partial religions rely on the hypnotic manipulation of undeveloped minds; the Integral Way is founded on the free transmission of the pain, natural, and immutable truth...Renouncing what is fashionable and embracing what is plain, honest, and virtuous, the Integral Way returns you to the subtle essence of life.^5
Here we see the doctrine of Partial religions developed. Buddhism is not a religion at all, but a partial religions created by misunderstanding or purposefully altering the teachings of Laozi to the Indians. One can progress in these partial religions, but only gain partial understanding and thus fail to become immortal and understand the truth of the Dao.
To the Chinese Daoists, Buddhist wisdom and the similarities to Daoism are both explainable by the fact that they are both the teachings of Laozi and thus not foreign at all, but the parts of Buddhism that disagree with Daoism are in fact alterations, misunderstandings of the uneducated barbarians. Thus, any practice adopted from the Buddhists or any sutras copied aren't really copies or adoptions at all, but Daoist practice all along.
The Santian Neiji Jiang is mainly a cosmological sutra composed slightly later than the Hua Hu Jiang. The first half is an explanation of the cosmos as they relate to the Three Heavens, but the second half is a vicious attack on Buddhism. According to the Sutra, Laozi went west to teach the Barbarians but they were stupid, uneducated, and of poor moral character. They were ungovernable and without ethics so Laozi placed more prohibitions on them -such as chastity and abstinence from alcohol- and they could only partially realize the truth of the Dao, which they called emptiness. Thus Buddhism is a deviant religion. Furthermore, Buddhism is based on being reborn and passing through death, and thus inferior to Daoism by it's very nature.^6
Of course, the Buddhist responded by saying that, "no, it is the other way around," and writing their own stories^4, which I can unfortunately find no examples of. However, I would speculate that they largely had the same content but in reverse, it was the Chinese who were of poor moral character and thus refused to follow the precepts.
In any case, it is interesting that it was not the Buddhists that attempted to nativise the religion, but their opponents in order to discredit them. No, Buddhists were always insistent that their tradition was from India and could be traced back to the Buddha himself. While this led to more than a few persecutions, in the eyes of the Buddhists, their doctrine was true and important, delivered by the Buddha and his Bodhisattva disciples.
Disregarding the many sutras written in China (notably those copies of Daoist ones and the Pure Land Sutras, though some of the later were written in Gandhari or Khotanese) perhaps the most notable attempt at linking the traditions back to India, of exoticising the tradition, was that of the early Ch'an (Zen) masters. Ch'an is primarily a descendant of the Dhyāna schools of Chinese Buddhism, themselves a group of schools centred on meditation and the earlier Nikāya Buddhist schools (or at least, the Chinese interpretation of them), but had fused with the Prajña texts and Mahāyāna ideals as well as adopting Daoist techniques. We can see then that Ch'an is a uniquely Chinese form of Buddhism, however Ch'an places a significant emphasis on lineage, more than perhaps any other form of Buddhism, and so it was problematic for it to be a native development. Ch'an was likely founded by a teacher of Shen-Hsui or one of their teachers, but was -in legend- founded, or rather brought to China, by a South Indian (or perhaps Iranian) Monk called Bodhidharma.^7 Bodhidharma was the first Patriarch of Ch'an but was also the Patriarch of Buddhism in an unbroken line that dated all the way back to the Buddha Śakyamuni himself and included Ānanda, Aśvaghoṣa, Nāgārjuna, and Vasubandhu.^8 Thus, Ch'an was not a fusion of Daoist and Buddhist practice, nor was it a native development, but the teachings of Śakyamuni himself passed through a number of Indian Arhats and Bodhisattvas. Of course, they were not the only school to do this. Pure Land also claimed to be descended from Śakyamuni who taught his disciples the way to enlightenment through Amittābha/Amitāyus.^9
Anyway, that's a brief version of the fascinating and bizarre history of attempts at nativising Buddhism and exoticising native developments. I honestly hope you find this interesting, even if it is somewhat unrelated, sources under the cut.
Chen, Kenneth K. S. Buddhism in China: A Historical Survey. pg. 35 Princeton (N.J.): Princetown University Press, 1973.
ibd. pg. 48
ibid. pg. 51
Mollier, Christine Buddhism and Taoism Face to Face: Scripture, Ritual, and Iconographic Exchange in Medieval China. Introduction. Honolulu, (H.W.), Hawaii University Press, 2011.
Anonomous, tr. Brian Walker Hua Hu Jing – Educate the Barbarians Sutra. Pg 28. San Francisco (CA): Harper San Francisco, 1995.
BokenKamp, Stephen R. Early Daoist Scriptures. Pg.190-230. Berkely and Los Angeles (CA): University of California Press
Chen, Kenneth K. S. Buddhism in China: A Historical Survey. pg. 350-354 Princeton (N.J.): Princetown University Press, 1973.
Anonomous The Denkoroku. MT. Shasta (CA). Shasta Abbey.
Chen, Kenneth K. S. Buddhism in China: A Historical Survey. pg. 338-345 Princeton (N.J.): Princetown University Press, 1973.