On the front and back sides of the kei (a Chinese musical instrument), a tsukiza (a hitting area) in the shape of a double-petaled lotus with eight pointed petals is placed in the center. On the right and left sides of the tsukiza, there is a lotus pond represented via an arabesque-like pattern that symbolizes the flow of water, from which lotuses stem out. Different from a relief-like representation method, most lines are drawn with a spatula. However, the patterns are drawn in a free, flowing manner and different motifs are applied to each of the front, back, right and left sides. This design closely resembles that of a lacquered inner box of a container for Issaikyo sutras of the Nanatsudera Temple in Aichi. Since the sutras were transcribed during the period from 1175 to 1178, it can be inferred that this kei was also created around the same period.