Sake Flask, 1500s. The grape design painted on these wine flasks reflects the popularity of grapes and wine during the Muromachi period; Japanese Zen clerics enjoyed grapes during this period, and Ichu Tsuzo (1349- 1429) and Saiin Shunsho (1358-1422) wrote poems about their appreciation for other artists? grape ink paintings. On these wine flasks, the vividly brushed leaves and bunches of grapes suggest that the artisan referred to a particular grape painting.