Shosaikan-Syosaikan Seiran Blue is one of two Sailor-made inks from the Shosaikan pen shop based in Tokyo with the other being a green-yellow. They are both in the lovely Sailor Tall or Vase bottles. I visited the store in 2018 on my trip to Japan; it’s a beautiful and spacious store with lots to offer (and lots of high end pens!). Before visiting the store, I acquired this ink via a forwarding service.