Both of them have not really met or interacted in canon. Probably because they don't exist in the same series. Though, this ship is a very popular crossover ship for the two fandoms. This is possibly because of how very similar they are to each other. Both of them are also known as one of the popular characters on their respective fandoms. By appearance, both of them have a scar on the left side of their face due from getting burned by their parents. They also share a similar color scheme, which is red that symbolized their ability to use fire with their bare hands.
Zuko and Shoto also share some similar personalities. Both of them are not very good when it comes to interacting with other people. They would even get embarrassed when talking to a large group of people or getting confused. They are also known for being the cold or anti-social person in their group of friends which are Team Avatar and the Dekusquad. During competitons or duels, they are mostly competitive and would want to win to get their fathers' attention. They are also intelligent or skill-minded when it comes to fighting their opponents.
They also share similar backstories which are the main reasons on why this ship became very popular. Both of them have a sibling (Azula and Toya Todoroki) who has an ability to use blue flames or rather have a stronger ability to use fire than them. Their siblings are also known as one of the major antagonists on both series. Both of them also have an abusive father who they really despise and they both want to prove to them that they are both stronger and independent than they are right now. They also have a mother who they really love so much though they became absent to their teenage years due from also getting abused by their father. Both characters also have rivals who they want to surpass or capture, who are Aang and Izuku Midoriya, but later befriends them in later episodes.
This ship mostly got popular when Shoto Todoroki was first introduced in the anime. Many fans started to compare them from one another because their similarities. There is also an ongoing joke on both fandoms that they might be long-lost siblings or scar twins. Some fans would even prefer this ship platonically or as friendship rather shipping them romantically. Most fanarts will show them being comfortable to one another and having someone who can they finally relate to. Some fanarts show them with Aang and Izuku (who are also very similar).
Even though this crossover ship is popular on both fandoms, it often get overshadowed by their popular ships. For Zuko, Zutara and Zukka. For Shoto's, TodoDeku and TodoMomo. This ship isn't very popular when it comes to fanfictions due for them seeing more of a friendship type.
|SHIPS||het||Azaang • Hakya • Harutara • Jetara • Jinko • Junko • Kakku • Kataang • Kummi • Maang • Maiko • On Jaang • Ra Min • Satoph • Sokkla • Soko • Sukka • Taang • The Doph • Tokka • Toko • Ty Laru • Ty Lokka • Ty Luko • Urkem • Urzai • Yukka • Zuki • Zutara|
|slash||Jetko • Rozin • Sokkaang • TodoZuko • Zukaang • Zukka|
|femslash||Azutara • Katoph • Mai Lee • Maizula • Rangshi • Tophuki • Tophzula • Tyzula|
|CHARACTERS||male||Aang • Sokka • Zuko|
|female||Azula • Katara • Mai • Ty Lee • Toph|