Does anyone know this?

Not sure if it was tagged as shounen-ai but its probably a psychological.
They were stepbrothers. One of them had black hair. The other maybe red hair? (Ill use that to refer to him but Im not quite sure)

Im pretty sure this scene was in the first few chapters: Red hair had rice on the corner of his mouth and black hair ate it.
I think red hair was the MC of the story. Later in the story he talked about how he regrets letting his younger brother become so weird. And Im pretty sure his friends also told him how weird their relationship was. (They weren’t dating or anything. Just a super weird sibling relationship.) I think black hair was in love with him because red hair always favoured him.

The main point I remember and why Im looking for this is because at the end one of them died. I think it was the red haired one. Maybe a car crash?

I know I really don’t remember a lot but maybe someone knows this.