For the American counterpart to this game, go here.
Why the Ouendan don't do anythingThe first thing that just bugs people about this series is that the title characters just do their little routine instead of helping the target do what they're doing. The explanation is that they're on shifted dimensions or something like that. So, why are they on shifted dimensions? Because they're Reapers or Angels. Their mission isn't to help these people— it's to increase their Vibe. This also explains why the final mission never features new characters. Only the people they've already "helped" have a high enough Vibe to see the Ouendan, much less fire a music lazer.
Ippongi Ryuta is Sol BadguyCompare This◊ to This◊ Relatively simple - after cheering for a while, he finally graduates highschool and goes into the fields of biochemistry and biotechnology. BAM! He invents Gears, goes from bad ass to badass bookworm with a sword, and uses Sol Badguy as an alias.
Shinta Kikuchi is the relative/genderbent alternate universe equivalent of Makoto Kikuchi.Think about it. Both are quite androgynous, and have careers in dance. They're also part of the Shipping Wars within their own universes, and can be quite brash. It's just that Makoto decided to actively pursue her career to change her image, while Shinta just had his job semi-thrust onto him, but just had the extra motivation to join.