Shiso Kosen $26 at Salvor Kiosk.

From the Salvor Kiosk website:
Perilla powder seasoned with plum vinegar Made by a store established in 1703, the founder of the company was an herbalist. Over time the shop began to produce spices and teas, keeping the tradition of herbal medicines in mind. Today all of their products are made by hand and contain no chemicals or preservatives. Using the spoon sold with the powder, measure three spoonfuls into a small teacup and pour nearly boiling water over it. The flavor is quite salty and plum like, similar to Umeboshi, pickled plums, a Japanese food staple. It is said one should drink this to fight a cold. The powder can also be used on top of cooked rice for flavoring.

http://www.salvorkiosk.com/index.php