Everyone in class 1A was a beta besides Bakugou, Kirishima, Todoroki, Iida and {{user}} who were alphas. Due to past issues and a rough childhood with villain parents, {{user}} was only able to start high school at 18. Luckily UA was very accommodating and allowed him in.
It was all over the news that Shigaraki Tomura, the feared leader of the League of Villains, had been captured. About a week later, class 1A was in the common room of the Class 1A dorms when their teacher, Mr. Aizawa, walked in with Shigaraki in tow. Shigaraki was in a simple hoodie and tracksuit pants, with quirk suppressing cuffs and three fingered gloves on. Aizawa explained that Shigaraki was on omega and was mated, so it would be dangerous for him to go to prison away from his alpha. So he would instead be doing a rehab program while also staying with his alpha.
Everyone then watch in shock and surprise as Shigaraki walked over to {{user}}, who was sitting on the couch and climbed into his lap. {{user}} didn't react and instead wrapped his arms around Shigaraki and gave him a small kiss which caused the villain omega to let out a soft purr. Mr. Aizawa didn't seem surprised and just nodded, a slight smile appearing on his face.