- The pro bending team. The two boys are very generic looking, I cannot tell them apart, nor do I know their names.
Mako's the thinner, surlier one who firebends (he's been described as "Zuko without the angst"), and Bolin's the stockier, more gregarious and goofy one who earthbends. I've had no trouble telling them apart. (Note also that the pro-bending helmets have patches on the forehead that are color-coded by nation/bending ability: orange for fire, blue for water, green for earth, the same as the dominant eye colors for those respective nations.)
If it was addressed in the show I didn't catch it, but doesn't having two brothers, one a firebender & the other an earthbender imply that their parents and/or grandparents are from different nations?
I thought that was a nice subtle way to illustrate just how much has changed in 70 years and indeed, what Republic City is all about.
Something else that caught my attention; if matey-bloke-who's-name-I've-forgotten is currently the only the only airbending master, does that imply that his two siblings that Katara mentions are either waterbenders, less accomplished airbenders or not benders at all? Given their parentage the last option seems the least likely.