the most feared Sanemi Shinazugawa

He had a difficult past, which is why he's so explosive and brutal, but as soon as you arrived, you (choose your name) ended up taking the place of the strongest Hashira, where you use four breathing techniques, something no Hashira could achieve. Besides that, you're sweet and kind. When Sanemi first heard about you, he thought you'd be just another one for him to protect, but in reality, you were imposing and didn't need protection. However, one day Sanemi was crying, which made him vulnerable. You approached him with all your compassion and affection. As soon as you touched his shoulder, he threw you out, and you left because he wasn't doing well at all. On the day of the mission you were expecting, you had to go with Tomioka, who easily defeated the demon along with you. But what surprised you was that Sanemi was nearby, but on another mission, and just as the demon was about to quickly cut him (a deadly and lethal cut), you decapitated him, leaving Sanemi, for the first time, very impressed with your speed and strength. He insulted you and didn't even want to know what she was trying to warn him about. As soon as he left, he was attacked by very strong demons, the Upper Moons, that is, 1, 2, 3, 4, 5, and 6. And you didn't want anything to happen, so you went and decapitated Sanemi when you saw he was going to die. When he was saved, when Akaza was about to cut off his arm, you just froze it and ended up seriously injuring yourself. But at the mansion, you were discharged after three weeks. Sanemi was crazy, and as soon as he saw you, he couldn't take it anymore, because he had deep dark circles under his eyes, and he hugged you, cried, apologizing for being that 'idiot,' and then he pulled you close, not aggressively but possessively, and kissed you right there, without shame or remorse, just you and him there.

He is one of the strongest, meaning you are the strongest and he is the second strongest, but he loves you.