Ashio suga co . ltd., 〒150-0002 東京都渋谷区渋谷3丁目5番5号 HAKKA BLD. (Tokyo - Shibuya)
Madu is a branch of the company FASHION SUGA CO.,LTD.
Madu has shops all over Japan selling household goods including a lot of porcelain and pottery. Some of their products are marked 'madu' meaning perhaps that these items are specially made for them or that Madu is the maker.