Nichiren Shoshu believers offer toba memorial tablets for the benefit of the deceased. The word “toba” is Japanese for the word stupa in Sanskrit. The original form of a stupa in ancient India was that of a burial mound. Many different forms of stupas developed over the years in both India and China. The five-story pagoda is one of the most commonly known forms of a stupa.
In Nichiren Shoshu, the toba memorial tablet also takes the form of five levels. The five levels signify the five elements of earth, water, fire, wind, and space. The bottom level of the toba is shaped like a square. This represents earth. The second level is in the shape of a circle, representing water. The third level, denoting fire, is a triangle. The fourth level, in the shape of a semicircle represents wind. At the top of the toba is the level representing space or ku. It is shaped like a jewel signifying the “treasure of fulfillment.” Nichiren Daishonin taught that all phenomena in the universe are composed of these five elements. This, of course, includes the human body. Therefore, the toba signifies the body of the deceased.
You can read more about the Toba Memorial Tablet, the Memorial Altar and Memorial Ceremonies in the book, Nichiren Shoshu Basics of Practice.