Cold-brewed sencha is a sencha exclusively for cold brewing, which is "gogumi" (blended) so that it will be the most delicious when brewed with water. The higher the tea is served at a higher temperature, the more the bitter and astringent components dissolve out along with the sweetness and umami components. If you extract it with cold water, the bitter and astringent ingredients will not dissolve out easily, but it will have a slightly grassy and fishy smell, and the overall taste will be unbalanced, so it won't taste very good. Cold-brewed sencha is a seasonal tea that is finished with a unique combination and manufacturing method so that when served with cold water, it has a good balance of umami and richness, sweetness that gradually spreads, and moderate bitterness and astringency.