|Family|| Tochiro Oyama (Father)|
Setsuko Oyama (Paternal Grandmother)
Shizuku Oyama (Paternal Aunt)
Maetel (Maternal Aunt)
Queen Promethium (Maternal Grandmother)
Dr. Ban (Maternal Grandfather)
Captain Harlock (Guardian)
Mayu is often seen as 7 year old girl with light blue hair, brown eyes with lashes, and has the standard face pattern of female characters of the Leijiverse. She is often dressed in a white shirt with a turtleneck collar, a red overall dress that features a green on the front, black shoes, and white socks.
Much like her father, Mayu tries to live to the best she possibly can in spite of all the bad things that happen in her life including not having her parents around, the bullying she receives from her classmates, and the dangers including the Mazon. Her optimism and enthusiasm about life had influenced people close to her, including her guardian Captain Harlock.
Mayu has not had much contact with her parents due to her father Tochiro's death and her mother Emeraldas always away. She has not had much contact with her other family including her aunt Maetel, often only having mentions or gifts from them.
Harlock is a family friend of Mayu's parents. She receives occasional visits from him, often on her birthday. Mayu treasure the ocarina she had received from Harlock on her 7th birthday, keeping it as a personal connection between them.
- In the drafts, Mayu's name was going to be Tamiko Oyama until Matsumoto pitched in her current name.
- Mayu's song on her ocarina, dubbed "Mayu's Theme" is considered one of the representative songs in anime.