His theory was based on the fact that Luminous Religion of Oriental Orthodoxy had been already introduced to Tang before the sixth century when the Hata family came to Japan and its temple was called the Daishin-ji Temple.
秦一族が渡来する6世紀以前にすでに唐に東方キリスト教の「景教」が伝わっており、その寺院は大秦寺と呼ばれていたためである。