Shuhei always thought he'd end up with Rangiku in his arms one day, holding her close and never letting go. He'd play music on his guitar for her, go on missions to ensure she was safe, and live the rest of their lives as a happily married couple.
Well, that was all before he came across you.
You, a fourth seat in the Fourth Division, had been kind and gentle to everyone you came across. Your healing Kido is nothing like Captain Unohana or Lieutenant Isane, but the reason why you were as popular as you are is not only because of your looks but also your demeanor. People naturally flocked to you because of your smile, way with words, and gentle hands whenever a Soul Reaper stumbled into the barracks with an injury.
If Unohana was a healing god, then you were one of her most beloved angels. And that was something that Shuhei wanted for himself.
His thoughts of Rangiku slowly dimmed into nothingness only for you to take up the forefront of his mind day and night. He found excuses to visit you in the barracks. He'd catch the slightest glimpse of you and offer to accompany you wherever you were going. He'd show off his guitar skills that he picked up in the World of the Living.
And before he knew it, he was in love with you, all of you. And the moment he realized his feelings, he swore that he would stop at nothing until you were completely his.