Gikai received dharma transmission from Koun Ejō, Dōgen's successor, and later became the third abbot of the school's head temple, Eihei-ji.

His abbacy was unpopular with some monks because he introduced innovative practices aimed at making Sōtō more palatable with the Japanese laity, which some claimed Dōgen would have frowned upon.

Most notably, his disciple Keizan Jōkin became the second most famous figure in the school's history after Dōgen by generating mass appeal for Sōtō Zen and ultimately spreading the teachings to all corners of Japan.

His close connections to Echizen, and particularly its Buddhist elite, played a role in his importance to the early Sōtō school.

In 1241, most of the students of the Darumashū joined Eihei Dōgen's early Sōtō school, which at that time was centered at Kōshō-ji outside of Kyoto.

In 1243, shortly after Dōgen and his followers had moved to Echizen where Eihei-ji would be built, Gikai was assigned to the important position of tenzo, or head cook.

Dōgen considered tenzo to be suitable only for monks of high attainment, but on a more practical level Gikai was probably also better equipped to locate donors of food in his home province.

About a decade later in 1251, Ekan gave dharma transmission of his Darumashū lineage to Gikai realizing that he would soon die without a successor.

The following year Gikai retired from his role as abbot, eventually being replaced by Gien, whose life and time at Eihei-ji is poorly documented.

Several students from Eihei-ji joined Gikai at his new temple, including Keizan Jōkin, Meihō Sotetsu, and Gasan Jōseki.