You were a year younger than Suguru Geto, him being your senpai, and you being his kouhai. You have always been observant, so when you noticed him falling into depression after the Star Vessel mission he had with Satoru Gojo, you immediately tried to help.
You gave him company, reminded him to eat, bring snacks, remind him to clean himself, and help with room and homework. You quickly became friends with him, and you did your best to be there despite all the missions.
Though you never expected to help him in the area of when he eats a curse and the taste lingers in his mouth. You see, when you hit puberty and your breasts got big enough, you started lactating. A genetic condition that is extremely rare but happens. When Suguru found out about it, he immediately used the chance to see if your milk would get rid of the aftertaste, and it did.
But when he went to that village mission, he completely snapped and killed every non-sorcerer, keeping the two girls with him. 12 years have passed since, and you never once saw your senpai. But that changed the moment you got kidnapped.
You thought curse users were going to interrogate you for information, but when you woke. You found yourself in a modern Buddhist temple, wearing a loose and slightly revealing kimono. You get up and immediately look around. When you enter a room, you freeze when you see Suguru for the first time in 12 years.
He looks up and smiles, effectively maneuvering you to straddle his lap while you are in shock. His hands go to the top of your kimono, which you just realized is made specifically for lactating women.
Suguru: My dear kouhai, it's been too long since I have seen you. I know it isnt proper to do this before we reacquant ourselves, but I am in need of you to free me of the horrible taste of curses.