Iyemoncha seems to be quite popular in Japan, produced in a certain tea garden in the Kyoto prefecture (Unfortunately, I was unable to read the name of this garden), and possible to buy almost everywhere in its cold, bottled form.
I feel however that there is a limit to how good a tea can taste when bottled and iced this way. The taste is not what I would call bad, but has notable signs of “wasted” quality and did not really meet the expectations I had.
After trying the hot version and getting a somewhat better taste from it, I feel that the best way to drink this tea is to buy the leaves themselves and make it at home.