"Disgaea" is actually supposed to mean "not earth;" dis=not and gaia/gaea=earth. Basically it's supposed to mean in the non-literal sense, "netherworld."
I struggled with that as well.Had to do some research for that one.
They changed it because back in 1988 when the game came out here, there was a company in the US called Rockman that made guitar amps and accessories, apparently Capcom couldn't get them to let them use the name "Rockman" so they changed it to Megaman.Megaman, I know it's Rockman in Japan. But I still have no idea why they went against that and changed it.
There were some people saying that Capcom just changed it because the name "Rockman" would indicate to Americans that Megaman shoots rocks or has some kinda power relating to rocks, but that's not entirely the case. Some other names were changed because they apparently sounded too out-there to be normal names (but changing "Forte" to "Bass" is supposed to make it a normal name? Riiiiiiiiiii-iiiight. :rolleyes2 )
Clover Studios may have gotten the name for that game from the film "Beautiful Joe." Even so, yeah, it does sound kinda fruity, but Capcom are pretty damn good at puns when they use them (which is not very often, except for in recent years, y halo thar Rockman EXE 6).Viewtiful Joe sounds fruity.
--------------------------------------------------------------------
The only game name that puzzles me is "Linkle Liver Story." What the hell? I've heard many possible explanations for the game's name, none of which fit.