The Buddha’s disciple Śāriputra endeavored to become a Buddha for sixty kalpa fervently practicing the ways of the bodhisattva. Nonetheless, unable to withstand its tribulations, he gave it up to pursue that of the śrāvaka and pratyekabuddha.

As is written in “The Parable of a Magic City” (chapter 7 of the Lotus Sūtra), those who had established a relationship to the Great Universal Wisdom Buddha for a period of three thousand dust-particle kalpa, and those who had received the seed of Buddhahood from the Eternal Buddha for five hundred (million) dust-particle kalpa sank into the disillusionment of life and death. Although they had practiced the way of the Lotus, the King of Devils in the Sixth Heaven infiltrated the sovereign and those around him, so as to trouble and aggravate them, leading them to abandon their practices, and forever remain in the cycle of the six realms of delusion (hell, hungry souls, beast, asura, men, gods).

Ueno-dono Gohenji, A Reply to Lord Ueno, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 163