Captain Rainbow was one of the Wii's most original titles but sadly it never got localised for western release. While it's certainly possible to fight your way through the game without any knowledge of Kanji, a western translation is something fans have been holding out for for years - and it's now a reality.
The patch - which isn't totally complete yet, we should add - is the work of MarkAss and it builds upon the work of the previous translation group, Kirameki. It's clearly a work-in-progress and MarkAss (what a name) is open to feedback which will improve the patch.
Obviously there's a bit of jiggery-pokery required to get the patch running alongside the game (emulation on your PC via Dolphin is probably the easiest route), but it's well worth the effort. If you don't already own this unique Wii title then you'll be pleased to learn it's pretty cheap these days.