Whilst most mirin nowadays contains sugar and preservatives, our rice is naturally fermented with koji from just rice with some salt being added at the end of the process. Mirin is used to sweeten and gives a depth in flavour.
Typical values g per 100ml
Energy kJ: 796
Energy kCal: 187
Fat: < 0.5
of which saturates: < 0.1
Carbohydrate: 46
of which sugars: 35
Protein: < 0.5
Salt: 2.1