Gourd-shaped shumon 朱文 style seal introduced into Japan from China during the Song and Yuan dynasties. Today there are about ten paintings in Japan by artists such as Muqi (Jp: Mokkei 牧谿), Ma Yuan (Jp: Ba En 馬遠), and Xia Gui (Jp: Ka kei 夏珪) that, in their lower corners bear this seal. One theory has it that this seal was a collector's seal kanzō-in 鑑蔵印, belonging to Zen'ami 善阿弥 (1386-1482), a garden architect who lived during the Muromachi period. Other theory is that these paintings were not produced by a Chinese artist at all. Proponents of this theory claim that the paintings in question exemplify weak linework and a general artistic mood not common to Chinese painting. They thus suggest that this seal was employed by a Japanese artist named Zen'a 善阿 who painted in the style of these Chinese masters. The problems surrounding the two different theories, as yet, has not been satisfactorily resolved.