Kamen Rider Kuuga/Fridge

Fridge Logic

Why is it only the police, and not the military, who are engaged in fighting the Grongi?
- Because, be honest, would you waste probably hundreds of potential dollars/yen of property damage just to kill monsters that only appear once at a time? Also, the military would probably force the Grongi to pull the big guns and sent out the likes of Go-Gadoru-Ba and even N-Dabuva-Zeba himself to come out.

Just why does the series have a pumped-up, Hot-Blooded opening theme contrasting with a soft rock ending? The final episode drives the point home - Yuusuke, finally unburdened by the duty of being Kuuga, shows his kindness to a group of children with the ending theme playing over. The two musical themes of the show present the character of Yuusuke Godai - a kind man forced by circumstances to become a fearsome warrior who would save the world.
The fact that Godai has 2000 skills would come in handy, since Kuuga has 4 different forms and varying weapons, each having their fighting style and strategy.