Hosshaku-kempon refers to when a Buddha discards the provisional identity and reveals the true identity. The Daishonin, who behaved as the votary of the Lotus Sutra, revealed the life condition of the True Buddha as His inner realization at the time of the Tatsunokuchi Persecution.
The Daishonin Himself makes reference to this in the “Opening of the Eyes”, where we can understand the meaning of the declaration “Nichiren discarded the life of the common mortal at the execution site of Tatsunokuchi and revealed the life of the True Buddha of Kuon-ganjo which is the Origin of the True Buddha’s Enlightenment in the Infinite Past, and then went to Sado Island”(declaration). After the Tatsunokuchi Persecution, the Daishonin inscribed the Gohonzon which is the object of worship. This behavior is nothing other than the behavior of the True Buddha.
On October 12^th 1279, as the True Purpose of the Buddha’s Advent into this World, Nichiren Daishonin inscribed the Dai-Gohonzon of the High Sanctuary of the Essential Teaching which should be embraced by all living beings in the Latter Day of the Law. He passed away peacefully on October 13^th 1282.