From On Reciting the Daimoku of the Lotus Sutra, considered by Soka Gakkai as one of the Ten Major Writings

"Answer: First, with regard to the object of devotion, one should inscribe the eight volumes of the Lotus Sutra, or one volume, or one chapter, or simply the daimoku, or title, of the sutra, and make that the object of devotion, as is indicated in the “Teacher of the Law” and “Supernatural Powers” chapters of the sutra. And those persons who are able to do so further should write out the names of the Thus Come One Shakyamuni and the Buddha Many Treasures, or fashion images of them, and place these on the left and right of the Lotus Sutra. And if they are further able to do so, they should fashion images or write out the names of the Buddhas of the ten directions and the bodhisattva Universal Worthy and the others." -- On Reciting the Daimoku of the Lotus Sutra, considered by Soka Gakkai as one of the Ten Major Writings