MD: We wanted to include a story about brothers in Korra, which is where the idea for Mako and Bolin came from. They also illustrate how family and culture had become more mixed, seventy years after the original series. Mako and Bolin’s mother came from the Fire Nation and their father hailed from the Earth Kingdom,but they both were killed when Mako and Bolin were young. Forced to grow up to soon, Mako protected and shielded Bolin from the darker side of the world. This is why Mako grew to become more cynical and serious of the two, while Bolin still remained childlike and naive.

-Book 1 air art of the animated series