Shodai is the Japanese term meaning the practice of chanting Nam-Myoho-Renge-Kyo.
Fifty-ninth High Priest, Nichiko Shonin, stated the following on
the practice of Shodai:
“The Daimoku that we chant must be performed attentively and diligently. When chanting, we should not have trivial thoughts in our minds. The speed should not be too fast and our pronunciation should not be slurred. We must maintain a medium pitch and chant calmly, resolutely and steadily. There is no established number of Daimoku that we must chant. The amount depends on individual circumstances. . . . When we chant, the entire body should feel a tremendous surge of joy. We must persevere until we become totally one with the Gohonzon.”
(Nichiren Shoshu Basics of Practice, p.19)
On the first Sunday of each month, temples around the world join the High Priest in Kosenrufu* Shodai. Kosenrufu Shodai was started by 67th High Priest Nikken Shonin. He did it on the 1st Sunday of every month. And he gave guidance for local temples to do the same. Our current High Priest, Nichinyo Shonin, continues this tradition. The purpose is to practice for Kosenrufu in unity with priests and lay believers.
*Kosenrufu means to widely declare and spread True Buddhism (Basics of Practice Glossary, p. 125)