As Yang and Katsuki are from different series, even though both of their home universes have superheroes, they have never met. Yang and Katsuki are both blondes that have red eyes (part-time for the former) and explosive powers who are easily angered and have some kind of involvement with the main character. They both go to top-notch schools where they learn to fight using their powers. They also eventually have some significant moments which leads to them changing and becoming somewhat less angry. For Yang it was losing her arm, and for Katsuki it was being defeated by his rival.
Some of the people in Yang’s group of friends are a little similar to Katsuki’s in traits, personalities, and backstories. Orange also appears to be Bakugo's main theme color as he wears it alot, it seems to be one of Yang's main theme colors as well. They both also seem to struggle with their insecurities internally and have a close relationship with the main character. Furthermore, both of their insecurities manifest in external rage, that ends up playing a part in their respective powers. The two both also have fire-based powers.
The two also have minor arcs where they're viewed as "villains". Yang and Katsuki also both have weapons that are on their arms that can shoot out explosions or bullets. The two also have a close if albeit strained relationship with an older male mentor figure, Yang with her Uncle Qrow and Katsuki with All Might. Yang has a close relationship with Ruby because she is her sister and her teammate, whereas Katsuki's close with Izuku because he is his childhood friend and classmate. Coincidentally enough, Katsuki's english voice actor also voiced Shay D. Mann, the bandit who tried to hit on Yang in volume 5.
Explosive Hot-Heads is one of the well liked ships of the RWBY/MHA crossover fandom. Some fanfics and art have the two existing in the same universe, where they fight. Some fans hope to maybe see a game one day where the two fight against each other. Because the two are so similar a lot of fans think the two would drive each other crazy if they ever did end up together. It has a small fanbase on deviantart and tumblr.
- Explosive hot-heads comes from the fact that both Katsuki and Yang are hot-heads and both have explosive powers.