My adventures in the land of snow and ice are quite different to another seeker´s, my dear old friend. Long ago in the Russian hills, near the Arctic Tundra, a famous pole explorer Father Tiresias found the regal Hogweed by a marsh. He captured it and brought it home. But that is another story, and not quite a happy one like mine.
The old man from whom I acquired the cartridge said " We must keep this place in secret", and he gave me his last spare cartridge and vanished into snow flurry. I will never reveal his hiding place.
Oh yes, I have known that Japanese site for a long time but I´m not quite sure if it´s a true NOS. That´s why I bought a genuine one.
Anyway, whatever the case, I strongly advice to grab on those while they are available.