December of 2011 was the last time Pilot released any new colors in the Iroshizuku line. We received four colors then, and now, almost a year later we’re getting three more: Takesumi, Shinkai, and Amairo.
The three new inks will come in the famous Iroshizuku bottle that we all know and love and is planned for a November release in Japan with no confirmation on a US release date. It will be available through Engeika, a very reputable seller from Japan who ships to the US, so importing it shouldn’t be a problem.
Thanks for Michel for the tip and Rocky for the translation!