Kids aren't into those type of cartoon characters these days, they're into anime and blood and guts,lol.
But seriously,,,,kids are also very opinionated, really I think it'd be harder to market a new product as this to kids than it would to adults. Are you gonna be the kid caught at school drinking a PLKD looking uncool, while your classmates drink monster drinks, and soda. Might be a good idea to parents, but to kids? That's yet to be proven. Might be "now Tommy, eat your vegetables!" kinda thing as mom pushes a pleasant kids H2O across the table.
Also disney has bottled water for kids, and Ricos characters are akin to disney characters.....