"Zaku" is one of the brands of Shimizu Seizaburo Shoten, a brewery located in Suzuka, a town usually more associated with Formula 1 than with sake. Most likely, the Ise-Shima Concept sake was created to commemorate the G7 Ise-Shima Summit held in 2016; while the label doesn't mention the rice used, the brewery's website states that they use Kaminohana, a relatively new type of rice produced in Mie Prefecture, polished down to 55%.
It has a very noticeable fruity aroma (strawberry and pineapple), its nose can be described as firm and sweet. The Ise-Shima Concept is quite sweet; however, the alcohol taste and pungency become more pronounced as the temperature of the sake rises. It has a full flavour with notes of pineapple and a slightly bitter mouthfeel. Crisp and spicy finish with a sweet aftertaste.
I bought two of them by accident and couldn't be happier.