Let's chant "Nam-Myoho-Renge-Kyo".
Daimoku is a mantra that is chanted as the central practice of all forms of Nichiren Buddhism.
There are two types of Daimoku: the Daimoku Chanted during the Former and Middle Days of the Law, and the Daimoku to be chanted during the Latter Day of the Law. Although Bodhisattvas Vasubandhu and Nagarjuna themselves chanted the Daimoku during the Former Day of the Law, they did so to practice for themselves only.
During the Middle Day of the Law, Nanyue, Tiantai, and others did chant the Daimoku; however, they did it only for the sake of their own practice and not for teaching others. This type of Daimoku was practiced [in order to observe one's mind] based on the theory [elucidated in the surface meaning of the words].
Now, in the Latter Day of the Law, the Daimoku that Nichiren chants is different from that of previous ages. It is the Nam-Myoho-Renge-Kyo of the practice for oneself, and the practice for others. These five characters of the Daimoku possess the five major principles for interpretation:
name, entity, essentials, function, and teaching.