Every Buddha in the universe is a follower of Shakyamuni Buddha except SGI "Buddhas".

How strange!!! Nichiren teaches:

"Moreover, when I examined how long the various Buddhas had spent accomplishing the practice needed to become a Buddha and how long Shakyamuni had done so, I found that some of the other Buddhas had spent three asamkhya kalpas or five kalpas, but that Shakyamuni Buddha had been in the sahā world since major world system dust particle kalpas in the past, a great leader who made it possible for all people to establish the connections needed to attain Buddhahood. No one in this world who was in any of the six paths of existence was ever able to establish such a connection with any other bodhisattva of any other land.

The Lotus Sutra states, “The persons who heard the Law at that time are each in a place where there is one of these Buddhas.” T’ien-t’ai says, “The Buddha of the western land is different [from the Buddha of this sahā world], and those who form a relationship with him are also different. It is impossible to assert that the living beings of this sahā world are related to Infinite Life [Amida] Buddha in the way that the father and son are related.” Miao-lo comments on this, “Amida and Shakyamuni are two different Buddhas to begin with. . . . Moreover, the living beings who in past existences formed a bond with these two respective Buddhas represent two different groups, and the methods used to convert and guide them are not the same. Forming a bond with a Buddha represents the process of birth, while the maturing of one’s Buddhist practice represents the process of upbringing. If the Buddha with whom one forms a bond and under whom one’s practice matures is different [from the Buddha of this sahā world], then one cannot establish the father and son relationship with the Buddha.”

Nowadays all the people of Japan are waiting for Amida Buddha to come and take them to his realm. This is as absurd as to expect that one can feed mare’s milk to a calf, or to use a piece of tile as a mirror and hope to see the reflection of the moon in it!

Again, if we consider the question of how long it has been since these various Buddhas attained the fruit of Buddhahood, then we will find that there are some who became Buddhas ten kalpas ago, others a hundred kalpas or a thousand kalpas ago. But in the case of Shakyamuni Buddha, the lord of teachings, it has already been a period of numberless major world system dust particle kalpas since he became a Buddha of perfect enlightenment and complete reward. 

Thus Come One Mahāvairochana, the Thus Come One Amida, the Thus Come One Medicine Master, and all the other Buddhas of the ten directions are followers of Shakyamuni, the lord of teachings and our original teacher. He is like the moon in the sky that is reflected in ten thousand different bodies of water.

The Vairochana Buddha seated on the lotus pedestal with other Buddhas surrounding him in the ten directions, who is described in the Flower Garland Sutra, and the Thus Come One Mahāvairochana of the Diamond Realm and the Womb Realm, who is described in the Mahāvairochana and Diamond Crown sutras, are attendants who stand on the left and right of the Thus Come One Many Treasures, the Buddha described in the “Treasure Tower” chapter of the Lotus Sutra. They are like two high ministers in attendance on a worldly ruler. And this Many Treasures Buddha is a follower of Shakyamuni Buddha, the lord of teachings of the “Life Span” chapter."