Unflavored sake is acceptable without Hashgacha. Flavored sake (e.g., Coconut Sake) and sake which states on the label that it was aged in wine casks require Hashgacha. Nevertheless, due to potential Kashrus concerns, it is preferable to only consume premium sake labeled as Honjozo, Ginjo or Daiginjo.
The O/U certifies many, but NOT ALL Country Crock Products. Country Crock products with the O/U symbol are certified Kosher while the Country Crock products