While Kennin-ji was established in 1202 and is usually considered the first zen temple in Japan, it was under the control of the powerful Tendai School based on Mount Hiei, resulting in the imposition of certain norms that were not present at Kōshō-ji.
It was abandoned only seven years later in 1243 when Dōgen and his students left under poorly documented but possibly hostile circumstances to found Eihei-ji in modern-day Fukui Prefecture.
Initially functioning as a hermitage, Dōgen gradually attracted students until in the summer of 1232 enough were present to hold their first ango, an intensive three month practice period.
Ekan's disciples included Tettsū Gikai, Gien, Giun, and Giin, all of whom would come to be important people in the early history of Sōtō Zen in Japan.
There is some evidence to suggest that Dōgen was forced to leave by the Tendai establishment due to perceived competition, but a lack of clear sources makes the precise reason for their departure impossible to pin down.