Sweet sake we define as sake that is obviously sweet, like a dessert wine, not ones that have a touch of sweetness. These can include sparkling sake, Nigori (cloudy) sake, or Kijoshu (a special type of sake that is very sweet) but also fruits sake like Umeshu (plum sake) and a variety of citrus sake.
It's important to note that Japanese citrus sake are not as sweet as a Westerner might expect. They are usually refreshing and crisp and taste great over ice or with soda water. Another great option is to heat them and enjoy them hot in the winter months.
Sweet sake are best paired with desserts with a similar level of sweetness.