Consider this:

• Śāriputra will become a Buddha called Flower-Light “after a countless, inconceivable number of kalpas from now.”
• Mahā-Kāśyapa will become a Buddha called Light after he sees “three hundred billions of Buddhas, of World-Honored Ones, makes offerings to them, respects them, honors them, praises them, and expounds an innumerable number of their great teachings.”
• Subhūti will become a Buddha called Beautiful-Form after he sees “three hundred billion nayutas of Buddhas, makes offerings to them, respects them, honors them, praises them, performs brahma practices, completes the Way of Bodhisattvas, and becomes a Buddha on the final stage of his physical existence.”
• Kātyāyana will become a Buddha called Jambunada-Gold-Light after he first makes “offerings to eight hundred thousand millions of Buddhas” and after their extinction erects “a stūpa-mausoleum a thousand yojanas high, and five hundred yojanas wide and deep.” After all that, “he will make the same offerings to two billions of Buddhas.”
• Maudgalyāyana will become a Buddha called Tamālapattra-candana-Fragrance after making “various offerings to eight thousand Buddhas” and after their extinction he will “erect a stūpa-mausoleum a thousand yojanas high, and five hundred yojanas wide and deep.” Once he’s completed that, “he will make the same offerings to two hundred billions of Buddhas.”
• Pūrṇa, the son of Maitrāyanī, will become a Buddha called Dharma-Brightness after becoming the “most excellent expounder of the Dharma … under the future Buddhas of this Kalpa of Sages.” And after that kalpa ends, “he will protect the teachings of innumerable Buddhas.”
• Kauṇḍinya, Uruvilvā-Kāśyapa, Gaya­Kāśyapa, Nadī-Kāśyapa, Kālodāyin, Udāyin, Aniruddha, Revata, Kapphina, Bakkula, Cunda, Svāgata and the twelve hundred Arhats will become Buddhas called Universal-Brightness after asaṃkhya kalpas of making “offerings to six billion and two hundred thousand million Buddhas.”
• Ānanda will become a Buddha called Mountain-Sea-Wisdom-Supernatural-Power-King after making “offerings to sixty-two hundred million Buddhas and protecting the store of their teachings.”
• Rāhula will become a Buddha called Walking-On-Flowers-Of-SevenTreasures after making “offerings to as many Buddhas, as many Tathāgatas, as the particles of dust of ten worlds.”
• The eight-year-old daughter of the Dragon King Sagara instantly became a Buddha in the Spotless World in the south.

When I recently pondered why the dragon girl was different, I had an Eureka Moment.

Śāriputra and the other disciples whose future Buddhahood are  predicted far in the future had been students of the Buddha’s expedient teachings.

As Śākyamuni explains to Śāriputra, “Under two billion Buddhas in the past, I always taught you in order to cause you to attain unsurpassed enlightenment. You studied under me in the long night. I led you with expedients. Therefore, you have your present life under me.”

The eight-year-old daughter of the Dragon King Sagara was taught by Mañjuśrī.

“Mañjuśrī said, ‘In the sea I expounded only the Sūtra of the Lotus Flower of the Wonderful Dharma.’ ”

That is the power of the Lotus Sutra.

Namu Myōhō Renge Kyō