I also use it regularly.Heisei 23
i.e. 2011 Mokou CoalTouhou Yarinsai / Takenoeki / Nikutamasoba
Convention / Producer of the Charcoal / Illustrator Comes with an exclusively-illustrated tag with the recognizable faces of the manufacturer and the regular user.
'Manufacturer' refers to Mokou, while 'regular user' refers to Mystia.