_&?

Its a romance, slice of life type of manhwa. The only rhing I remember is one of the main characters has an illness and they both have suffered through tragedies in their lives. Appearance wise the girl has dark red-purplish short haird and the boy has blond hair but dark roots and he has his hair in a middle part; they are both tall with the boy being slightly taller than her. They are in high school. Its very sweet wholesome but with a little bit of angst due to the characters' personal problems. I can't remember if one of them was held back by a year or something.

Ya'll I need help. It's a korean manhwa where they were both children at the start of the story but the girl who has black hair is actually someone who remembers her pastlife and the boy who she became friends with fell in love with her. They soon die from an accident and reincarnate as opposite genders, the black haired girl becomes a guy and the brown haired boy becomes a girl. And the brown haired boy remembers her from the last life.