So-rin on the roof of Daigo-ji's pagoda

Here’s a close-up picture of the spire called so-rin. This part of the tower, not the whole tower, is the one that evolved from stupa, a hemispherical mound built in ancient India around the 3rd century B.C. to inter and venerate the ashes of Shiddhartha Gautama, the founder of Buddhism, who lived in the 5th century B.C.

The five storied pagodas in Japan, therefore, must have been originally built to enshrine the Buddha’s ashes or relics as an object of worship. Overtime, the significance of the pagodas as well as their location on the premises has changed - first in the center of the temple but later where it stands out well as a symbol and landmark of the temple - though they remain as one of the indispensable structures for many temples.

Well-surviving examples of early stupa are found at Sanchi, India. Sanchi is the oldest extant Buddhist sanctuary. Stupa 1, especially, has been preserved well. Its mound is topped with a parasol-like structure which is said to have intended to honor and shelter the ashes or relics of the Buddha. It is famed for its rich decorative work on the four monumental gateways called torana that provide access.

For more about Buddhist monuments at Sanchi which include Stupa 1, visit UNESCO’s World Heritage Convention site.

This web site shows a CAD image of the so-rin at Horyu-ji temple. The one at Horyu-ji’s pagpda alone has four scythes attached on it. It’s a bit of a mystery and nobody knows exactly why. Many say it must be a kind of charm against lightning; others insist it hopes for good harvest.