I am not sure what's the definition of Sencha in the strict sense of the word. I just believed... or I "wanted to" believe that Sencha is the one produced in Japan. However, non-Japanese Sencha have been seen here and there throughout the world, which puzzled me more...
Anyway, this is about Japanese Sencha. Actually, Sencha is not only one. As far as I know, there are several types.
<Sencha (standard)>
It is most popular and common green tea in Japan.
The shape of high-quality Sencha is beautifully rolled into needle shape, and the color keeps beautiful dark green. They are more seen grown at mountain side in Kyoto or so.
<Fukamushi-Sencha> also called "Fukamushicha"
"Fukamushi" refers to “longer steam”. When the tea is produced, the heat is applied to stop oxidization. For Fukamushi one, the time to steam is longer than standard sencha, which makes the leaves a bit more crumble and the tea steep quicker. They are more seen grown at flatland in Shizuoka and Kagoshima.
<Kabuse-sencha>also called "Kabusecha"
Kabuse means “covered”. Sencha is usually grown under the blue sky. But for Kabuse-cha, they are covered for about a week or so, which is shorter than Gyokuro and Matcha. This method will give the tea more umami.
(When the leaves are covered, they will keep L-Theanine, a kind of amino acid, which will give the tea more umami.)
<Kamairi-sencha>also called Kamairicha
Most of tea in Japan, the leaves are steamed after being plucked. But in this case, the leaves are pan-fired. It’s mainly produced in Kyushu, the south part of Japan. As you can see, they are curled unlike the standard one. (”Kama” means pan, and ”iri” means fired.)
Moreover, there are various varieties of tea. The taste of Sencha differs depending on which type of Sencha you will choose and which variety is used for the tea. Every time you sample tea, you may find different taste. When you come to Japan, enjoy an authentic Sencha. And you can tell this is, what I believe, the McCoy:-)