|The following section/s may deal with the main plot of the anime.|
During her Life, she was a caretaker/guardian for the Wakanae Family. Marcia and the Wakanae family lived in peace until Souta's parents both died. To prevent shocking Souta, Marcia decided to keep the deaths of his parents a secret to him, which caused Souta's identity crisis and depression. Prior to her retrieval, she was kidnapped by a black market dealer and soon becomes a Wanderer. When confronted by Tsukasa Mizugaki and Souta, she attacks them. Marcia mercilissly attacks Souta by choking him, which leaves him emotionally scarred for the rest of his life. She is then terminated by Tsukasa with his close-combat shock gun.
Marcia was a loving caretaker to Souta. Although not much of her personality was shown, she was a bright cheerful gifted who wanted to make Souta happy. Afterall, she planned to make Souta's birthday party, and prove to him that his valuable memories about his family should not be forgotten.