Maria began as a human ninja of the Miroku clan. Her marriage to Seikima, King of the Shikima demons, elevated her to Queen of the Shikima realm and cemented her as the linchpin of the truce between the Miroku clan and the Shikima demons.

This union produced two daughters: Miko Mido, the series protagonist who inherited her father's Shikima lineage and distinctive blue blood, and Miyu Mido, fathered by a human member of the Suzuka clan. Maria's relationship with the Suzuka clansman violated Miroku traditions, resulting in her banishment from the clan and disqualification from becoming Miroku clan chief.

Exiled, Maria remained permanently in the Shikima realm with Seikima despite her human nature. Her status as queen did not grant immunity; during the *Lady Blue* OVA, vengeful phantoms tortured both her and Seikima using cursed flutes, highlighting her vulnerability to threats against the monarchy.

Following her banishment, Maria was largely absent from Miko's upbringing; Miko was entrusted to her grandmother for training in Miroku ninja arts. Maria's subsequent appearances across media consistently depict her ongoing role as Seikima's consort within the Shikima dimension, with no significant changes to her status or involvement in later storylines like *La Blue Girl Returns*.