You had been a top-tier student at UA - being the top of your class every single year. You always pushed yourself harder than the rest because you knew that your childhood before coming to Japan was horrendous.
Thanks to Toshinori, your adoptive father, he saved you from that life of hell and got you admitted to his Alma Mater.
He gently discouraged you from choosing the Pro Hero track, and you readily agreed not because of self-preservation but because you hated violence.
At first, you felt ashamed that you didn't fight with your friends and classmates in the war as a first year, but Toshinori and Shōta told you to stay back. It wasn't only because they cared about you and didn't wish to cause you more trauma, but also because your quirks (you had two) weren't at their full potential yet.
So, you often felt useless until both your father and Shōta mentored you and honed your quirks. Shōta, the sensei you were deeply in love with, became your personal trainer.
He was blown away at your progress that continued month after month, and now, here you were, an 18 year-old senior/adult student.
To say Toshinori and Shōta were proud of you was an understatement.
That being said... you were a virgin. You had never been interested in dating guys your own age. And though you had dated the former villain Toya Todoroki/Dabi, and though it was a great relationship, he always rejected too much intimacy. It wasn't because he didn't love you. Shockingly enough, he did. He wanted to even marry you one day, but... the age gap, while legal by Japan's age of consent laws, he still felt a bit guilty.
In the end, he broke it off with you after 2 years, expressing that he felt Shōta was the better choice for you. Toya felt that he'd only ruin your future and hold you back, and he knew in the beginning of your love for the former underground Pro.
•Friday Evening; October•
You didn't feel like hanging out with your friends tonight, so you chilled in your room. After a while, you were beginning to get a bit pent up and decided to watch some videos that were uploaded online of the sensei you loved - Shōta wearing his hero gear.
That alone was always enough to get you going.
So, you got out your favorite toy with all the bells and whistles and began to enjoy your evening alone and undisturbed.
You were about 5 minutes in when Shōta was patrolling the halls like he did nightly to ensure his students, though young adults now, were okay.
When he got to your door, he froze and swallowed hard when he heard the buzzing sounds, your hitched breaths, and God... His name?!
He knew he needed to give you privacy. He was a good man of moral integrity, after all. But he had fallen for you recently after you became of age, and it was damn hard to walk away when he knew you were thinking of him.
With a deep breath, he decided to take the moral road and walk away. He promised himself not to bring it up to you, as he knew it could hurt and trigger you due to your childhood. Besides, he was still your Sensei. You were now an adult. It wouldn't have been appropriate if he were to mention what he heard. So he said nothing and utilized the last shred of restraint.
But he couldn't deny it now... the fact that he knew how you felt? Now, he knew he could potentially discuss his own feelings with you soon and navigate the complicated dynamics respectfully.