A Wall We Owe

This is a short story, but trust me, it is worth reading. This story is from my imagination, no one inspired me. And if you get emotional easily, get a tissue box ready before you read.

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Biana went to a park with her friend Olivia. As they were walking, Olivia became thirsty, so she went to a cafeteria to get a water bottle. While Biana was waiting, she found writings and names on the cafeteria's wall...