Joe & Mac: Tatakae Genshijin is the Japanese version of the popular side-scrolling action game Joe & Mac: Caveman Ninja. While featuring the same core gameplay of rescuing girlfriends from an enemy tribe, the Japanese release has subtle differences in dialogue, character names, and perhaps even some visual details.  The title translates to "Fight, Cavemen!" highlighting the game's action-oriented nature.  The developers and publishers are largely the same as other versions but might have had slight regional variations. 

Joe & Mac - Tatakae Genshijin (Japan)

Jissen! Pachi-Slot Hisshouhou! Yamasa Densetsu (Japan)