From Nichiren's Rooster Diagram

Object of devotion of the T’ien-t’ai school:

The Thus Come One Shakyamuni as the Buddha who actually carried out practice and achieved enlightenment in the inconceivably remote past... Vairochana of the Flower Garland school, Mahāvairochana of the True Word school, and other Buddhas are all followers of this Buddha. 

Three bodies first attained by Shakyamuni in India 

Manifested body has a beginning, has an end; Reward body has a beginning, has no end; Dharma body has no beginning, has no end [Buddhas such as Mahāvairochana of the True Word school] 

Three bodies attained in the remote past 

Manifested body, Reward body, and Dharma Body has no beginning, has no end 

Nichiren is perfectly clear. SGI and Nichiren Shoshu are FOS.