Beyond the Brick Wall

Zoey had no idea what problem she got herself in.
Her life started falling apart once Xavier left her.
So one day, just before she lost all her hope, she put her life in the hands of a stranger. She jot down her decision on a small note, asking if she should end it.

Xavier left his best friend. He left her for his own benefit, not thinking about her at all. The only time he realized this, it was too late, she had gone and left him already.
So when he found a note from a stranger telling him that she wanted to kill herself, he had this urge to help her, guide her back on track to her life as he failed to do for Zoey. He told her that he'd always be there for her.

They never knew, even just slowly, that their broken heart was being sewn back together.