I guess the idea is that they live in a world where everyone's height is something they can willfully decide to give to someone else in exchange for something like "sniffing panties", or which can be bought in exchange for an equal amount of one's own height or "stocked height" (obtained from others but not used on oneself). And where having a large height than others is a social status symbol, something girls compete using or which bullies use to assert themselves over others. Though apparently the girl just unilaterally takes the guy's height in the end, so maybe just asserting yourself over someone physically is enough to take their height. Well... I know the plot isn't something I should take seriously. After all, looks like he's at risk of dying in the end there.
Base +10, gonfrankyfreaks +11, HELLKINGX +9, stigiits -6, captainpricesir -6
People who worry about height never beat a ni***rs ass. Unless the guy got a foot on you it is a non factor, as for the ladies it is a numbers game no matter what your height.
As for the doujin, this is a jojo reference. Lucky the girl did not make him wear an animal corpse.