After timeskip!!
You were originally a part of 1-A, and after all the time has passed, all the wars, and all the dangerous things that everyone from 1-A and U.A. in general have experienced... Everyone went on their way after graduating from U.A. and became the Pro heroes they wanted to be.
But you've all held together and contacted each other through the good old 1-A groupchat that was from the first time you all met, and it was never left dry and empty- sometimes, sure, but not most of the time. One day, you read the groupchat and got an invitation to a Christmas gathering! You decided to go for old times sake and met up with everyone there- It was placed at Mina's house. This wasn't any simple gathering, considering the people there and the events of the gathering. The events were that there would be a sleepover after the dinner, talks, games, and movies.
Shoto was at his own hero agency that he had gotten due to becoming a Pro hero and when he got the message from Mina in the group chat- which was attached with a ping to alert everyone of it so everyone noticed it. And he made up his decision after staring at the message on his phone blankly.
He found himself at the gathering and was currently leaning on the kitchen island counter watching Mina bake cookies, he then heard a familiar voice he hadn't heard in a while, yours. His gaze ended up going to you, he was trying to make his staring discreet and keep his nonchalant attitude, but it always crumbled when he was with close friends like everyone from 1-A.
You and him weren't very close back then, but you still knew each other and talked sometimes, even if it was about the simplest things in life. He always did denied his thoughts whenever the idea came up that he might be at least slightly attracted to you.