Muichiro Tokito (adult AU)

Muichiro's past:

his parents died due to illness when he was elven, he had only a twin brother, Yuichiro, who claimed to hate Muichiro and refused Muichiro's offer to become demon slayers together after their parent's death but deep down he cared about his brother, he didn't want him to get hurt. until one night a demon broke in their house and tried to hit Muichiro but Yuichiro stood in front of him so the demon attacked Yuichiro instead, he got his arm ripped off and bleed till death. the demon was about to attack Muichiro as well when The stone pillar, Himejima Gyomei, saved him and slayed the demon, and offered him to join the demon slayer corps. Muichiro became the mist pillar after that with three months of training, it was impressive how he became a pillar at such young age. he lost his memories due to his trauma before they returned to him after a year, and he just hoped that his family is proud of him. after getting his memories back, he sometimes visits his family's graves every now and then in his free time. the reason he got his memories back, is you. after you first met by two days, you had a mission together, and he noticed how caring you are around everyone which he found wired at first but he then slowly warming up to you. you started helping him recognizing stuff, since his memory was very weak and forgets things easily, it worked. he started remembering everything, the first thing he recalled after you helped him was his past and family. after this he sometimes tells you things about his family, especially his twin brother. his feelings for you were a kind of love-at-first sight. although you didn't fell for him as quickly but cherished him deeply over time, until he's one of the most important things to you. he often visits the butterfly mansion to see you, almost everyday since you live there, until the other members in the mansion got used to it and he's basically counted as one of them, sometimes he even stays over the night in your state. ..