One of the two major schools of zen in Japanese Buddhism. The school (Jap., shū) was founded by Dōgen (1200–53), who saw it as a transmission of the Ts'ao-tung school of Chinese Ch'an; hence, the name Sōtō, which is the Japanese pronunciation of the characters ‘Ts'ao-tung’. Dōgen established a style of Zen that made no distinction between practice and attainment; for him, the object of sitting was not to attain Buddhahood, but to manifest one's innate Buddha-nature through the act of sitting itself. Thus, unlike the Rinzai school that used riddles (kōans) to spur practitioners to enlightenment (bodhi;satori), Dōgen downplayed the goal-oriented nature of meditation and aimed instead at the realization of a reality that was always already present to those who would notice it. At the time of Dōgen's death, the Sōtō-shū consisted of a small group of disciples headquartered in the remote mountain Eihei Temple in Echizen prefecture. As it was so small, and as Dōgen himself rejected the concept of ‘school’ (Jap., shū) entirely, it is difficult to speak of the group he left behind as the Sōtō-shū. The development from small band of followers to one of the largest schools of Japanese Buddhism really stems from the activities of later generations of his disciples. After Dōgen's death, his chief disciple Koun Ejō (1198–1280) succeeded him as abbot of the Eihei Temple. Ejō himself picked a younger monk named Tettsū Gikai (1219–1309), a man who had already been marked for leadership by Dōgen himself, to nurture as his own successor. However, Ejō's tenure as abbot was marked by a routine and unbending adherence to Dōgen's teachings and practices, but without Dōgen's vision and leadership, and the temple fell into decline. Differences between Ejō and Gikai appeared from the beginning, but Ejō, out of deference to Dōgen's wishes, did his best to train his younger colleague to take responsibility for the community.
Gikai travelled in China from 1259 to 1262, and when he returned with sophisticated architectural drawings and plans, Ejō put him in charge of temple construction. Five years later, Ejō stepped down as abbot and handed the leadership over to Gikai. Almost immediately the monks broke into pro- and anti-Gikai factions. Those who opposed him thought he was abandoning the simplicity and focus of Dōgen's ideal monastic life, squandering time and resources on new buildings and external decor. Gikai even went so far as to introduce Shingon liturgies into the life of Eiheiji, contaminating the ‘pure’ Zen of Dōgen. Finally, in 1272, the monks petitioned Ejō to resume the abbacy, which he did, and during his final years he successfully held dissension to a minimum. This set the stage for the division of Sōtō into two competing factions. After Ejō died in 1280, Gikai felt he should resume the abbacy, based on his previous experience and upon Dōgen's Dharma-transmission to him. Others within the community, uncomfortable with his progressiveness and (to their mind) over-accommodation with worldly concerns, wanted another of Ejō's prominent disciples, Gien (d. 1314) to succeed as abbot. The faction supporting Gikai prevailed, and he took up a second term as abbot of the Eihei Temple. However, the second wave of Mongol invasions (see Mongolia) in 1281 increased public demand for esoteric rituals for the protection of the nation, and Gikai was willing to make room in Eiheiji's regimen to meet this demand. His actions brought the simmering conflict to a head: open fighting broke out within the compound, and Gikai was forced to flee, leaving the office of abbot open to Gien. The Sōtō school was split. The Eihei temple, factionalized and concerned with maintaining the purity of its tradition, languished for a time, while the faction that went with Gikai out of the temple flourished. Gikai's careful cultivation of contacts with wealthy patrons and of good relations with other Buddhist groups, and his concern that his religious practice meet the needs of the times, paid off in terms of support, and he was able to found several monastic communities. Thus, for a time, the branch of Sōtō that dominated was precisely the one that did not follow Dōgen's single-minded Zen practice, but a mixture of meditation, esoteric ritual (see Esoteric Buddhism), and public service.