This reminds me of
The Quest of Ki, where I only kept the English title, since it was the one that was prominently displayed (the Japanese title only appears in the box art of the game and
at the very top. The title screen of the game only showed the English title.
In this case, however, it seems the Japanese title is the one that's prominently displayed, with the English title reduced as a subtitle (on both box art and the title screen). Mobygames suggests the title be
Chippoke Ralph no Daibōken: The Adventure of Little Ralph (but screw Hepburn, so it's
Daibouken). Wikipedia and GameFAQs suggest only the English title (with GameFAQs noting an
Also Known As: Chippoke Ralph no Daibouken: The Adventure of Little Ralph).
So....in the end, I actually am in favour of having the game name be what Mobygames suggests. If we're going to stick with one or another, then let's stick with the Japanese title, since it's the one that's prominently displayed.