In 1591 (Tensho 19), the year after his entry into the Kanto region, Tokugawa Ieyasu issued vermilion-seal patents to temples and shrines throughout Sagami Province. Shorenji received formal confirmation of twenty-five koku of temple lands, gaining official status as a venerable Koyasan Shingon institution under Tokugawa patronage. Protected by this recognition, the temple went on to serve as a Shingon dharma academy for Kanto, overseeing more than thirty sub-temples across Sagami Province.