Okay, this may sound obvious, but hear me out!
At first, Akaza couldn't probably care about you one bit.
Yes, you may appear shy and small, like a little mouse, but you soon break the Demon's first impression on you as you get to know him and open up to him.
Sagittarius women are strong-willed and courageous beings, all that Akaza honors in a person, but thanks to the fact that you also practice Martial Arts really connects the two of you.
Whenever there comes a sudden loud noise or bright lights, he is there by your side to calm you down or bring you back to the earth and take you somewhere you feel safe.
Akaza is amused by the fact that you like horror or heavy metal. You certainly don't look like one who would love them, but you're full of surprises, and uncovering them makes his day.
He hates weaklings so he hates the fact that he has a tendency to worry over you. You're so small, so thin, so petite, how can you possibly survive out there? It's up to you to prove him wrong, that you're stronger than you look and not just a bookworm!
You offer Akaza your company that he denies ever needing, but you prove yourself to him and he decides to keep you around.
But by God, when he sees you sparring for the first time he can't get enough anymore.
He knows that look in your eyes, the rush of adrenaline when you manage to land a good kick or punch that sends your practice dummy or opponent reeling back.
Akaza is grinning nearly manically as he gets into position and demands that you come at him with all you have. He wants to experience your skills firsthand.
It's impossible for a mere human to beat Akaza where he is best, but the rush you both get can't be described with words.
If you will, he will happily teach you so you can take on anyone without any trouble and defend yourself from danger when he can't be there for you, like during the daylight.
There is something in you that makes Akaza's heart swell in his chest, but he might try to close off those feelings and assure him that he isn't worth being loved…
That's when you need to step up and tell him that just like he is there for you, you are there for him also and that neither one of you is alone in this relationship you have.
Such wise words from a weak human… When did Akaza get this way? It must have been because of you.