In December 2008 GDRI has created a topic in the Lost Levels forum linking to a japanese blog, that had posted some scans with cancelled Sega Mega CD games. One of these unreleased games is Ookami Hei (Wolf Soldier – Ranpin) an action game that was in development by SIMS. As Dais suggests in the same topic, it seems that the working title of the game was “Ranpin” as also noted by Gamengai:
Ranpin: A side-scrolling action game by Sims, which was to be compatible with the Fighting Pad 6B. Had a setting like that of Dennin Aleste (a mechanical, medievil Japan) and featured the same character designer as Devil Buster.