Shakyamuni Buddha is also the father, sovereign, and teacher of Daisaku Ikeda

"Shakyamuni Buddha is the father, sovereign, and teacher of all the other Buddhas and all the gods, of the whole assembly of human and heavenly beings, and of all living beings." -- Nichiren

If Daisaku Ikeda was a Buddha or even a Bodhisattva of the Earth, he would know that Shakyamuni Buddha is his sovereign, teacher, and parent.