Margo

Margo (マーゴ, Māgo) is the major character of the special chapter pilot chapter We Were Born. She has a serious illness and Rita is said to be the only way to save Margo.

Plot
Mr. Mendel shows the picture of her daughter named Margo to Rita and he told her that she is the new sister of Margo. He told that, she was born with a condition and Rita said she will do anything to help. Mr. Mendel told to the father that Rita is a good girl and and he told the way for Margo to be healed.

Mr. Mendel went to his home and he asked forgiveness to Margo and she said "There is a meaning to live and each of us gets to decide" and she told to him she wants to write a story. A story about how each of the lives of the people have meaning.

Mr. Mendel
Mr. Mendel loves Margo so much that's why he wants her to be healed.