Junketsuko was originally called Sada-Chan, and was created for the game Souls & Steels by Kennodo Games. Sada-chan was rejected as a character design, and later made her first appearance in Stone Smash as Junketsuko.
In the game Stone Smash, one level of the game, which in and of itself is a reference to The Ring, hitting a certain block will provide a brief image of Junketsuko, while a barely audible voice whispers "Seven days...."
Junketsuko also makes a cameo appearance in Chousenshi Densetsu: Dynastie Rising. There is a well in the first level, which, when clicked with the mouse, will briefly transform into a white ring of light on a black background. When it returns to its well form, Junketsuko's hand will be holding on to the edge of the well.
Junketsuko appears on one of the tiles in the CC & SH set in Tilearade.