For all Gyokuro lovers and people who would like to get on the life with Gyokuro, it is a pretty easy way to enjoy it.  You do not need to care for brewing at all. 

There is a scientific background why an ice-brewing method keeps Gyokuro taste for such a long time.  The signature of Gyokuro taste is coming from umami of L-Theanine.  L-Theanine has very delicate taste and it takes long time to be extracted into water from leaf. 

In case of hot water brewing, water "cooks" leaf to force L-Theanine out, then the leaf locks remaining  L-Theanine in.  So when it comes to the second infusion, we are actually using "cooked" leaf, which makes tea taste like Sencha rather than Gyokuro.

Inside the pot of Shinobi-cha, both infusing and infused water keeps the temperatue around 4 Celsius.  The leaf cannot be cooked under this environment and takes time to infuse the tea contents.

After all the ice qubes melt, you can use hot water (70-80C) to brew the second.