Sanin-tei was a private school kept by the Sugawara clan, that had produced Monjo hakase (professor of literature) for three generations; SUGAWARA no Kiyokimi, SUGAWARA no Koreyoshi, and SUGAWARA no Michizane, during the early Heian period. Originally, the lecture was given in Sanin-tei, a study of the head of the Sugawara clan, but as the number of students increased, the lecture began to take place in the hallway (chumonro - covered entrance arcade) of Shinden-zukuri style - architecture representative of a nobleman's residence during the Heian period) -- That was why the lecture was called Kanke Roka (the hallway of Sugawara's house) and remembered in later ages.
Shosai-Ki' (essays of SUGAWARA no Michizane) in "Kanke bunso" (an anthology of Chinese-style poetry by SUGAWARA no Michizane) described: There was a study of about nine square meters in the southwest corner of the private residence of the Sugawara clan (the residence was called Kobai-Den (red plum blossom residence) in later ages. The residence was likened to Kita kandaijin-jinja Shrine in the present Shimogyo Ward of Kyoto City); The study had produced many monjosho (student of literary studies in the Japanese Imperial University) and Monjo tokugosho (Distinguished Scholars of Letters); and The name of the residence was Sanin-tei. As the preface in the Chinese poetry style composed by Michizane to "Fuso shu" (Chinese classics during the Heian period) described "my father Koreyoshi lectured on History of the Later Han Dynasty for his disciples in his Unkaku (study)," the lecture was considered to be originally given in the study Sanin-tei. Later, to cope with the increased number of disciples, the lecture room might have been changed from the Sanin-tei to the hallway -- the width of which was wide enough to be substituted for compartments by using partitions and tatami mats and so forth -- and the lecture might have been called the Kanke Roka and became widely known. The name Kanke Roka was mostly used among those who studied from the Sugawara clan as well as other men of letters mainly after Michizane died.
It was considered that the head of the Sugawara clan established the private school for lecturing on the Kidendo for students who were asking the head to teach them, besides performing his official duties at the Daigaku-ryo (Bureau of Education under the ritsuryo system). It reflected the social conditions at the time when instruction on the Kidendo was widely offered; on the other hand, such an act was obliged to involve a private relationship between master and disciple -- It was considered that the latter fact introduced a conflict between the academic clique from the Sugawara clan and those from the hakase who opposed the Sugawara clan, and that the latter made the Daigaku-ryo system only in name and promoted the formation of hereditary learning.
As a couplet in a poem titled 'Anraku-ji ni sanzu' (Visited Anraku-ji Temple) (contained in "Honcho zoku monzui" (Further Anthology of waka poems and prose written in classical Chinese) composed by OE no Masafusa in 1100 to Anraku-ji Temple (SUGAWARA no Michizane's mortuary temple located in Dazaifu) had it 'Ruiyo roka no matsuyo tari' (I was the last leaf in a heap of leaves in the hallway), it could be estimated that the school had been kept by generations of the Monjo hakase of the Sugawara clan and at least until the late Heian period.