Pure Land Buddhism and Its Purpose in The Initiates’ Book
To understand why Kenreimon-in would choose to forsake the world and seclude herself to a ten-foot square hut on Jakko-in proper, one must first understand her religion: Pure Land Buddhism. Pure Land Buddhism, unlike all other forms of Buddhism, is a faith-based religion, wherein one only needs to believe in Amida, and at the hour of their death call his name but ten times, and they will be reborn into the Pure Land. Kenreimon-in, who watched her mother and her son – Emperor Antoku himself – drown, was instructed to pray for the Heike spirits to give them a better rebirth.
Thus, Kenreimon-in removes herself from the only home she knew to live as a nun at Jakko-in, a temple located in the hills behind the village of Ōhara. It is through her prayer and enlightenment that she intends to give the Heike a happier rebirth. One of the biggest reasons that the Tale of the Heike exists is to appease the Heike spirits, and in ending the tale this way – with Kenreimon-in, the last of the Heike and their final hope, attaining enlightenment and appeasing the spirits of those of her clan whom she had lost to war, amongst other things – is extremely fitting, hence why I believe that Pure Land Buddhism was the perfect plot device for ending the Tale of the Heike.
Further Reading
If you’re curious and would like to learn more about Pure Land Buddhism, or even just Buddhism in general, I encourage you to check out these sources:
Baroni, Helen J. (2002), The Illustrated Encyclopedia of Zen Buddhism, Rosen. https://terebess.hu/zen/szoto/Baroni.pdf
Dobbins, James C., et al. “Shinran: An Introduction to His Thought.” Monumenta Nipponica, vol. 45, no. 4, 1990, p. 487., https://www1.udel.edu/History-old/figal/Hist138/Text/er/shinran.pdf.
Inagaki, Hisao, trans. (2003), The Three Pure Land Sutras. https://web.archive.org/web/20140512124959/http://www.bdk.or.jp/pdf/bdk/digitaldl/dBET_ThreePureLandSutras_2003.pdf
Traleg Kyabgon (2001), The Essence of Buddhism, Shambhala. http://promienie.net/images/dharma/books/traleg_essence-of-buddhism.pdf