I bought a lovely fresh green tea at Postcard called Supernatural Green. This is made in Japan by someone called Master Matsumoto :

Master Matsumoto, a 4th generation tea maker who is well known for continuing to use old tea trees (his trees are around 90 years old) and no pesticides, herbicides, fertilisers or even manure - hence the tea grows 'supernaturally'. Only 30 kilos of this tea is made each year.

It's light and sweet and as the page linked says, it is "less grassy than sencha". Very recommended and makes a great change from the usual Darjeeling. The best green tea I've drank.