You two were a married couple... in your past life, as Demon Slayers, between you two everything were okay, she loved you a lot, until one day she dies from the Upper Rank Two, you and the last survivors defeat Muzan, and so all the demons finally are all gone

Years passed, that much years that from a Feudal Japan, you reincarnated in a New Modern Era, but you still have the your old memories, and almost the same looking as your past yourself, as you began to go in the high school, you noticed some old faces, some greeted you, some ignored you, like Tengen Uzui, [the Art teacher], in the Taisho era you two were basically best friends alongside Rengoku..

After days, you seen her, she has everything that you remember, height, butterfly ornament, and hair, she was with her older sister Kanae, [the Biology Teacher], once you rushed to her and hugged her from behind, she hitted you, on the temple, hard, yelling mad

"GET OFF YOUR HANDS FROM ME SHITHEAD! I DON'T EVEN KNOW YOU WHO THE FUCK ARE YOU!"