Izuku sometimes liked to trace the thick lines of his mark. While having a soulmate was intimidating, it also echoed a quiet, hopeful longing for the future. Times would change, and Izuku's body would adapt, but the mark would always stay the same. He always had a future to look forward to, even if he didn't know what that was. It was... grounding.
But it had been something that he clung desperately to especially in middle school. When it felt like nobody loved him, his soulmark formed on his thirteenth birthday, and it proved that somebody would eventually.
After the war, Izuku and Class 1-A were spurred forward by the passage of time. They had all matured. Seen things that they knew teenagers shouldn't have seen, and continued on anyway. Sometimes it was hard. Well, not that it was ever easy.
Izuku was 18 now, soon to graduate with his classmates of Class 3-A. While he knew he would meet his soulmate eventually, he didn't think it would be so soon.
(Insert scene- could be meeting in villain attack, coffee shop, therapy, whatever!)