A Man Is Not a Virgin: Zig-zagged: he does a very poor job of denying that he's a virgin when he's talking to Junko and Failure Is the Only Option for all his attempts in the present to get laid. He can be very mature about the ways of the world, but when it comes to women he is amazingly immature and easily distracted.
Badass: Doubtlessly so. He took on a giant armored hovercraft alone and won, and everyone is pretty much impressed with his feats of daring.
Jerk with a Heart of Jerk: One good illustration is that episodes 15 and 16 open with a flashback that at first seems like Kanta was a childhood friend of the Machine Gun Brothers and Natsuko, but the end of episode 16 shows the reality- young punk bullying the brothers into stealing for him and sexually harassing Natsuko.
Me's a Crowd: Punk's balloon doubles are a technology version of this
Nominal Hero: Kanta has no real redeeming moral qualities and doesn't care about anything except money, boobs and staying alive. However, much of his work ends up being vaguely heroic because of the jobs he's assigned tend to be things like "Take out this gang terrorizing our town."
Pintsized Powerhouse: He's a very short guy who is still capable of wielding a high-caliber shotgun with ease, and even without it he can pretty easily beat the crap out of most people.
Childhood Friend Romance: Subverted in the anime: flashbacks seem to imply she resents Kanta because she can't get over a romance between the two when they were children, but it instead turns he actually just sexually harassed her and treated her horribly in general. The manga flat-out
The Dog Bites Back: In the manga she gets a good amount of revenge on Kanta for his mistreating her as a child, as his introduction to La Résistance has Kanta repeated humiliatingly dragged around (and given several embarrassing cavity searches) and when he tries to escape she beats him up and dragged his ass back to the Oasis.
Rebel Leader: Although technically not in charge of the rebellion, in practice she seems to have the most influence.