Regional Differences
Forgive us, we tried.
(Source: "Magic Knight Rayearth" US manual, Page 18)
Short version: Working Designs.
Long version: Working Designs rather infamously took two-and-a-half years to actually produce the US version of the game after licensing it, due at least in part to Sega losing some of the source code in a hard drive crash. Never fear, though - nothing could stop Working Designs from cranking up a game's difficulty!
(Source)