With a massive gap in time happening between Avatar: The Last Airbender and The Legend of Korra, fans are left to wonder what happened to their favorite characters after the conclusion of the first series. Fortunately, fans were provided answers to this gap through a series of graphic novels that were written with full canon approval from the series original creators. Toph Beifong, being one of the greatest characters in the entire show, nevermind one of the best benders in the entire Avatar-verse, found herself quite busy after her adventures with the Aang gang to defeat the Fire Lord concluded.
As fans may remember, Toph actually discovered an entirely new form of bending during the series, being the first person ever to bend metal. By the time the events of The Legend of Korra take place, fans get to see Toph's daughter, Lin Beifong, lead an elite squad of metalbenders known as the Republic City Police that help maintains order in the multicultural Republic City. Founded originally by Toph herself, the group acts as a final barrier of defense to help maintain peace in a city made up of benders and non-benders from every nationality. So how do we get from Toph inventing metal banding to an entire squadron of highly trained police? Luckily, this is where the Avatar: The Last Airbender graphic novels help to fill in the story.
Not long after the final episode of Avatar: The Last Airbender, the comic series sees Toph continuing her role as a teacher but this time it is not the Avatar who is her student. Instead, Toph has now taken on a whole slew of students, teaching a ragtag bunch of misfits the ways of metalbending. Founded in an abandoned firebending dojo, the Beifong Metalbending Academy first appears in The Promise Part One, with its story continuing in parts two and three. Being the first of her students, this technically makes Ho Tu, Penga, and The Dark One the first three metalbenders to ever exist besides Toph. While at first, these students struggle greatly to pick up even the basics of metalbending, things quickly change when the original firebending owners of the dojo return and challenge the class to a duel over who gets to keep the school. At this time the school was lucky enough to have a visitor, and a second metalbending teacher, who, believe it or not, is actually the only member of the Aang gang that can't bend. That's right, it's Sokka!
Through wild motivation and hard work, Sokka and Toph try to whip the students into shape, however, they have no luck and the day of the duel approaches fast. Realizing she is forcing her students to be something they aren't, just as her parents did to her, Toph decides to forfeit the school to the firebenders, however, her students seem to have a different plan. Something finally clicks, and her students come in bending metal coins through the air, hurling them around the room, ultimately winning the school in favor of the metalbenders. It is this school that eventually goes on to be the starting point that ripples into her future Republic City Police force.
Don't worry, Toph's time away starting an academy of her own isn't the end of her journey, and she links back up with the Aang gang to continue alongside them on more wild adventures as the Avatar: The Last Airbender comic series continues.