SGI has adopted a variant of Yogacara [Mind Only] derived from Wonhyo the father of Korean Yogacara Buddhism

http://en.wikipedia.org/wiki/Wonhyo

"Wonhyo spent the earlier part of his career as a monk. In 661 he and a close friend - Uisang (625–702, founder of the Korean Hwaom school) - were traveling to China where they hoped to study Buddhism further. Somewhere in the region of Baekje the pair were caught in a heavy downpour and forced to take shelter in what they believed to be an earthen sanctuary. During the night Wonhyo was overcome with thirst, and reaching out grasped what he perceived to be agourd, and drinking from it was refreshed with a draught of cool, refreshing water. Upon waking the next morning, however, the companions discovered much to their amazement that their shelter was in fact an ancient tomb littered with human skulls, and the vessel from which Wonhyo had drunk was a human skull full of brackish water. Upon seeing this, Wonhyo vomited. Startled by the experience of believing that a gruesome liquid was a refreshing treat, Wonhyo was astonished at the power of the human mind to transform reality. After this "One Mind"^[7] enlightenment experience, he abandoned his plan to go to China. He left the priesthood and turned to the spreading of the Buddhadharma as a layman..."

SGI's teachings reflect just  such a view: "Two women are sitting in the Ob-Gyn office. One is an expectant mother who had been trying to have a child for many years and has finally become pregnant and is expected to have a healthy baby in two weeks. The other woman has just been diagnosed with late stage ovarian cancer. To the expectant mother, the office is brimming with vitality and joy, the pictures on the wall evoke an abiding sense of well being, the receptionist is an angel of mercy, the doctor is a compassionate father figure, and the wait to see the doctor passes as if a moment . To the woman with late stage ovarian cancer, the office is a gloomy prison cell, the pictures on the wall evoke a sense of foreboding, the receptionist is curt and uncaring, the doctor;s bedside manner is disturbing, and the hour wait seems like an eternity.

From the perspective of the Lotus Sutra, Shakyamuni Buddha, Tientai, and Nichiren, the doctors office is thus: It simultaneously possesses all Ten Worlds, their mutual possession, One Thousand Factors, and Three Thousand Realms in an ever changing panoply, whose essence is the Eternal Buddha's Realm. Yogacara and SGI teachings derive from the mind of the common mortal while the Lotus Sutra teachings derive from the mind of the Buddha.