Todoroki and Bakugo learned that they were mates way back in middle school. However, they were never able to find their third mate. They spent years trying to find their missing third but, they were only met with loose ends. So, when someone Katskui hasn't seen since childhood transfers to U.A, things start to make sense. After all, how can they find someone who was in the U.S. T.W. mentions of abuse, drug usage cigarettes cursing maybe smut(not sure yet)