Kusha was one of the 13 Chinese Buddhist schools (汉传佛教十三宗) and one of the 6 Japanese Buddhism schools , introduced to Japan during Asuka

Asuka period

The , was a period in the history of Japan lasting from 538 to 710 , although its beginning could be said to overlap with the preceding Kofun period...

 and Nara period

Nara period

The of the history of Japan covers the years from AD 710 to 794. Empress Gemmei established the capital of Heijō-kyō . Except for 5 years , when the capital was briefly moved again, it remained the capital of Japanese civilization until Emperor Kammu established a new capital, Nagaoka-kyō, in 784...

. Along with Jōjitsu and Ritsu

Ritsu

The Ritsu school of Buddhism is one of the six schools of Nara Buddhism in Japan, noted for its use of the Vinaya textual framework of the Dharmaguptaka, one of the early schools of Buddhism...

, it was initially based on Nikaya

Nikaya Buddhism

The term Nikāya Buddhism was coined by Dr. Masatoshi Nagatomi, in order to find a more acceptable term than Hinayana to refer to the early Buddhist schools. Examples of these schools are pre-sectarian Buddhism and the early Buddhist schools...

 schools, sometimes known derisively as Hinayana

Hinayana

Hīnayāna is a Sanskrit and Pāli term literally meaning: the "Inferior Vehicle", "Deficient Vehicle", the "Abandoned Vehicle", or the "Defective Vehicle". The term appeared around the 1st or 2nd century....

. Kusha was never considered to be an independent school. It was considered to be an adjunct of the Hossō sect, due to the main works of both schools being ascribed to Vasubandhu

Vasubandhu

Vasubandhu was an Indian Buddhist monk, and along with his half-brother Asanga, one of the main founders of the Indian Yogācāra school. However, some scholars consider Vasubandhu to be two distinct people. Vasubandhu is one of the most influential figures in the entire history of Buddhism...

.

Buddhism was introduced into Japan from China. The school takes its name from its authoritative text, Dharma Analysis Treasury, the Abidatsuma-kusha-ron (Sanskrit : Abhidharma-kosa-sastra), by the 4th or 5th century Indian philosopher Vasubandhu

Vasubandhu

Vasubandhu was an Indian Buddhist monk, and along with his half-brother Asanga, one of the main founders of the Indian Yogācāra school. However, some scholars consider Vasubandhu to be two distinct people. Vasubandhu is one of the most influential figures in the entire history of Buddhism...

. The Kusha school is considered to be an offshoot of the Indian Sarvastivada

Sarvastivada

The Sarvāstivāda were an early school of Buddhism that held to 'the existence of all dharmas in the past, present and future, the 'three times'. Vasubandhu's states:-Name:...

 school.

Names commonly associated with Kusha are Dōshō (道昭 638-700), Joe (644-714), Chitsū (智通 ?-?), Chitatsu (智達 ?-?), and Genbō

Genbō

, also known as Gembō, was a Japanese scholar-monk and bureaucrat of the Imperial Court at Nara.In 717-718, he was part of the Japanese mission to Tang China along with Kibi no Makibi and Abe no Nakamaro...

 (玄昉 ?-746). Its teachings were commonly thought to be part of the Hossō sect.