Nichiren speaks about Eagle Peak more often and comprehensively after the Sado Island Exile [after 1274]. It is only natural that one's thoughts turn to the afterlife as one approaches death. Nichiren knew that his exhaustive efforts, hardships, persecutions, and endless debates would soon take their toll. It is a wonder that Nichiren lived as long as he did.
“Bodhisattva Never Disparaging was a practitioner at the initial stage of rejoicing; Nichiren is an ordinary practitioner at the stage of hearing the name and words of the truth *.”
Nichiren, like ourselves, had recently received the seed of Buddhahood from the Original Buddha (Honbutsu). For countless kalpas, we have neither heard the Law nor practiced the Lotus Sutra. This is not to say that our Buddha-field (Buddha-nature) is not fertile soil for the Buddha seeds but we have not encountered the seeds of Myoho renge kyo for a very long time. Being common mortals at the stage of Myoji Soku (first hearing the name and the words of the Truth or Myoho renge kyo), we have various worries and doubts, especially concerning the afterlife. These doubts and uncertainties come to the fore when we have a near death experience, lose a loved one, or are coming to the end of our lives. I am sure that even Nichiren experienced these feelings and he was acutely aware of the even more intense uncertainties experienced by his disciples and believers. For this reason, Nichiren made the afterlife an important part of his teachings after 1274:
"The way of attaining Buddhahood is just like this. Though we live in the impure land, our hearts reside in the pure land of Eagle Peak. Merely seeing each other’s face would in itself be insignificant. It is the heart that is important. Someday let us meet at Eagle Peak, where Shakyamuni Buddha dwells. Namu-myoho-renge-kyo, Namu-myoho-renge-kyo." 
"The moon sets and rises again; the clouds disperse and then gather once more. Even heaven must regret and earth lament that this man has gone away and will never come again. You yourself must feel the same. Rely upon the Lotus Sutra as nourishment for your journey, and quickly, quickly set out for the pure land of Eagle Peak so that you can meet him there!" 
"Surely your late husband is in the pure land of Eagle Peak, listening and watching over this sahā world day and night. You, his wife, and your children have only mortal senses, so you cannot see or hear him, but be assured that you will eventually be reunited [on Eagle Peak]." 
"The priest Nichigyō’s death was indeed pitiful. I recited the Lotus Sutra and chanted Nam-myoho-renge-kyo for him here in Minobu, sincerely praying to Shakyamuni, Many Treasures, and the Buddhas of the ten directions to receive him on Eagle Peak." [1274?]
"Now you must shun and abandon this heartless world, entrusting yourself to the Lotus Sutra, in which the late Shichirō Gorō placed his faith, and quickly reach the eternally abiding and indestructible pure land of Eagle Peak. Your son’s father is on Eagle Peak; his mother remains in the sahā world. I sympathize with the feelings of the late Shichirō Gorō, who is in the interval between the two of you." 
"As you well know, a sutra says that the boy Virtue Victorious,1 who offered a mud pie to the Buddha, was later reborn as King Ashoka, who ruled over most of the southern continent of Jambudvīpa. Since the Buddha is worthy of respect, the boy was able to receive this great reward even though the pie was only mud. Shakyamuni Buddha teaches, however, that one who makes offerings to the votary of the Lotus Sutrain the latter age for even a single day will gain benefit a hundred, thousand, ten thousand, million times greater than one would by offering countless treasures to the Buddha for one million kalpas. How wonderful then is your having wholeheartedly supported the votary of the Lotus Sutra over the years! According to the Buddha’s golden words, in the next life you are certain to be reborn in the pure land of EaglePeak. What remarkable rewards you will gain!
This is a mountainous place, remote from all human habitation. Not a single village is found in any direction. Although I live in such a forsaken place, deep in this mortal flesh I preserve the ultimate secretLaw inherited from Shakyamuni Buddha, the lord of teachings, at EaglePeak. My heart is where all Buddhas enter nirvana; my tongue, where they turn the wheel of the Law; my throat, where they are born into this world; and my mouth, where they attain enlightenment. Because this mountain is where this wondrous votary of the Lotus Sutra dwells, how can it be any less sacred than the pure land of Eagle Peak? This is what [The Words and Phrases of the Lotus Sutra means when] it says, “Since the Law is wonderful, the person is worthy of respect; since the person is worthy of respect, the land is sacred.” The “Supernatural Powers” chapter reads, “Whether in a forest, beneath a tree, in monks’ quarters... in such places have the Buddhas entered nirvana.” Those who visit this place can instantly expiate the offenses they have accumulated since the infinite past and transform their evils deriving from the three types of action into the three virtues.
A suffering traveler in central India once came to Heat-Free Lake toquench p.1098the fires of anguish in his heart. He proclaimed that he could fulfill his desire, “as a clear cool pond can satisfy all those who are thirsty.” Although Heat-Free Lake and this place are different, the principle is exactly the same. Thus, Eagle Peak of India is now here at Mount Minobu in Japan. It has been a long time since you were last here. You should come to see me as soon as you possibly can. I am looking forward eagerly to seeing you.
How can I describe your sincerity? In truth, it is splendid!" .
There are more than 200 additional citations for Eagle Peak in the writings of Nichiren.
Every “advanced” religion and most primitive religions address the question of an afterlife. Most of Nichiren’s followers had the mistaken idea of an Eternal Paradise ingrained in their psyche due to the influence of the Pure Land teachings. This is not unlike we of the western world who have the Christian idea of heaven ingrained into our psyche. Even Chapter twenty-three of the Lotus Sutra takes into account the universal teaching of an Eternal Pure Land. The compassion and mercy of the Buddha and Nichiren is not to destroy the belief in this hopeful place, mistaken though it may be, but rather to utilize it so that we could believe ever more fervently in the Supreme Law.
“This is the place we live to enjoy happiness”. This is the place where we and our loved ones will be reborn to again experience the joy of the Law. Whenever the Buddha in the pre-Lotus Sutra teachings, let alone in the Lotus Sutra, talks about “assurance of no rebirth” or Nichiren talks about going to Eagle Peak, what they are referring to is no rebirth in the Lower Six Realms [Hell, Hunger, Animality, Anger, Tranquility, and Rapture].
Our prayers for the deceased are that they be free from sufferings, that they wake up from delusions, and that they attain Enlightenment (the Great Bodhi).
Eagle Peak is the intermediate state, the Land of Actual Reward, where we meet our teachers Shakyamuni Buddha and Nichiren Daishonin before again returning to this Saha World to sow the seeds of Buddhahood in the people's lives.
While here in the manifest state, we return to the Gohonzon, the Land of Actual Reward [Eagle Peak] here on earth where we again meet our teachers Shakyamuni Buddha and Nichiren Daishonin before we sow the seeds of Namu Myoho renge kyo within the lives of our families and friends. As Nichiren teaches, “There is no discontinuity between the three existences of past, present, and future.”