In a 1996 Gamest interview, some of the featured concept art shows designs for 2 characters named "Marisu" and "Teresu" who were not included in the final game. The game's character designer Mimori Fujinomiya commented:

"These were characters looked too much like ripoffs of the koropokkuru, so I abandoned them. Their personalities were too similar to Macky and Pentell, anyway. I do like their Robo-Dog though."