I just remembered a special plot from some time ago. I'm not sure if it is from a manga or some other media, but perhaps someone recognises it.
There are three main characters, one male person A and two female persons B and C. A and B are in love with each other, while A and C are friends or some other form of close relationship and C is also secretly in love with A but doesn't act on it obviously. Then in some tragic accident B dies and A despairs and eventually becomes suicidal. C helps him and eventually they become a pair.
I can't recall where I saw this plot but it kind of bugs me now, tips and directions would be appreciated. Thank you very much.