It seems to be freshly squeezed new sake. The first sip is not very sweet, but rather spicy and bitter. It has a freshness that makes it drinkable in a characteristic way.
Served at almost room temperature. Slightly sweet and easy to drink. There is no description on the bottle, but I wonder if it is junmai or junmai ginjo?
The last sake just before it is ready to be served. The taste is cohesive with a coarse sake yeast yeast, with almost no sweetness. It would have tasted better if it had been cooler.