The practice of retaining Buddhist images, which were intended as idols for worship, in zushi with the doors closed is quite unique in Japan even among East Asian countries where Buddhism has prevailed.
元来、礼拝のための偶像である仏像を扉を閉じた厨子等に納め「秘仏」とすることは、東アジアの仏教圏の中でも特に日本に顕著な現象である。