"For the first time" not "realizing"

"Those whose capacity to understand the Lotus Sutra was fully mature attained enlightenment during the lifetime of the Buddha, while those whose capacity was inferior and immature [could not attain enlightenment at that time. But they] reappeared in the Former Day of the of the Law, and by embracing provisional Mahayana teachings such as the Vimalakīrti, Brahmā Excellent Thought, Meditation, Benevolent Kings, and Wisdom sutras, they gained the same proof of enlightenment as that obtained by those of higher capacity during the Buddha’s lifetime.

Thus the Former Day of the Law possessed all three: teaching, practice, and proof, whereas in the Middle Day of the Law, there were teaching and practice but no longer any proof. Now in the Latter Day of the Law, only the teaching remains; there is neither practice nor proof. There is no longer a single person who has formed a relationship with Shakyamuni Buddha. Those who possessed the capacity to gain enlightenment through either the provisional or true Mahayana sutras have long since disappeared. In this impure and evil age, Namu-myoho-renge-kyo of the “Life Span” chapter, the heart of the essential teaching, should be planted as the seeds of Buddhahood for the first time in the hearts of all those who commit the five cardinal sins and slander the correct teaching. This is what is indicated in the “Life Span” chapter where it states, “I will leave this good medicine here. You should take it and not worry that it will not cure you.”