Kobo Daishi lived in the Heian Period (794-1185). Before his death, he was known as Kūkai. Among other professions including scholar, artist etc., he was a priest and was the founder of the Shingon (literally translated to "true word") School of Japanese Buddhism.
The Kirikane (截金 or 切金) technique has been used for this statue. This tehcnique is a traditional Japanese decorative technique used for Buddhist statues. It uses gold leaf, silver leaf, or platinum leaf cut into lines, diamonds, and triangles, resulting in a both delicate and splendid appearance of the Buddhist statue.