Juergen Specht - Photographs - Photos and Services by a German photographer living in Tokyo, Japan.Hihokan, or translated "House of Hidden Treasures" became popular in 1971 and you still can find them, practically unchanged since more than 30 years. Overview 1 of 11 In April 1971 Japan's first Hihokan which stands for "House of Hidden Treasures" opened its doors in Awa, Okushima. However, the ex