When it came to Chinese Buddhism, the distinctions between esoteric and exoteric traditions were not as profound. The School of Chan on the north was even widely recognized for its esoteric teachings of mantras and dharanis. Yi Xing was one of the most distinguished disciples for the Śubhakarasiṃha, and in his own way, he was instrumental in promoting the Zhenyan teachings, he later turned to practice Chan Buddhism. The school of Chan in Baotang, established by Baotang Wuzhu was also categorical in producing strong Zhenyan traditional followers.
Additionally, Tiantai of Zhiyi as well as the East Asian Yogacara school of Xuanzang was already practicing some degree of esoteric traditions and teachings before the Tang Mantrayana ascended to power. However, the most significant elements of esoteric Buddhism grew to prominence during the period of Tang esoterica.
Evidence has also emerged that goes ahead to suggest that esoteric Buddhist tradition also played a major role in influencing the growth of Daoism. The extensive adoption of the esoteric traditions during the Tang era can also be seen on the outskirts of the Chinese heartland like in Central Asia, Dunhuang, Nanzhao and Yunnan.
The spread of the religion outside China
Before the anti-Buddhist Persecution was implemented, Master Kukai visited China from Japan in a bid to understand the entire esoteric texts with the help of the three masters from India. Kukai was mostly taught by the pronounced master Hui-kuo from Japan. According to scholars, it only took master Kukai two years to study the complete teachings, after which he returned to Japan. The extension to Japan then became Shingon Buddhism, which is referred to as Dongmi “Eastern Esoterica”, since Japan happens to be on the east of China geographically. Other scholars suggest that the name originated as a result of the To-ji temple (Eastern Temple) situated at Kyoto, Japan, where the Shingon Buddhism School was established by master Kukai.
Another famous esoteric master known as Master Saicho, also known for introducing numerous other esoteric teachings to Japan. These teaching can be connected to the Japanese ancestry of Tiantai School, referred to as Taimi in Chinese, “Tai Esoterica”. Dongmi together with Taimi later grew into the two prominent systems focusing on Esoteric type of Buddhism in the islands of Japan.
Esoteric Buddhism was also introduced into the Kingdom of Goryeo in Korea (918-1392).
Liao, Song and Jinn era
The Zhenyan customs were widely adopted throughout the duration of the Tang dynasty and also into the early days of the Song dynasty (960-1279), though under some degree of limitations under the Song dynasty. Emperors of the Song dynasty continuously belittled translations efforts and Buddhism in general. However, esoteric deities such as the Mahavairocana, Thousand-armed Marici plus Guanyin were still growing in popularity as well as the utilization of dharani and spells.