First, the mandala is interpreted from an immanentalist view. It is seen not as representing the enlightenment of an individual transcendent Buddha, but as a ritual object that enables the practitioner to discern and actualize a realm of enlightenment already innate within oneself. Since the ten realms are depicted by the names of their representatives on the mandala, this innate realm of enlightenment is usually discussed in terms of the mutual inclusion of the ten realms:

The ultimate teaching of the Lotus Sūtra is the original inherence of the ten realms. When you face this object of worship, the realm of oneself, the realm of the Buddha, and the realm of living beings are all the essence of the Wonderful Dharma, the suchness which is original enlightenment. …

Now [in our school, we] do not establish contemplation [as the method of realizing the three thousand realms in one thought-moment]. We display it on a sheet of paper, so that one can directly see, in a single thought-moment, three thousand realms.

What is the true mutual inclusion of the ten realms? The teacher [Nichiren] said: “The seven characters that are chanted are the Buddha realm. We who chant them are the nine realms. When the cause and effect of the four teachings are demolished, the true cause and effect of the ten realms is revealed.” At that time, we are the unproduced triple-bodied [Tathāgata], the true Buddha (jitsubutsu), who dwells in the Land of Tranquil Light. The Buddha who appeared in this world was a manifested trace (suijaku), a provisional Buddha who benefits the beings through provisional teachings. Keep this secret! Keep this secret!

Such readings are on the one hand rooted in Nichiren’s treatise Kanjin honzon shō, which discusses the object of worship as embodying the mutual inclusion of the ten dharma realms and the importance of believing that one’s own deluded thought-moment contains the Buddha realm. (Page 330)