Maria Shiratori commands the Earth Defence Class from her position as class representative of Hinobori Elementary's Class 5-3. She activates their classroom command center by inserting her medal into a slot on her desk, coordinating strategy and issuing orders to the three pilots battling threats.

Of mixed heritage—quarter-French and quarter-Japanese—she aspires to be a painter like her father. Her strong-minded and responsible personality suits her leadership. She exhibits deep concern for her classmates' safety, especially the hot-blooded primary pilot Jin Hyuuga, leading to heightened emotional distress during critical battles; she cried openly witnessing Raijin-Oh and Ken-oh sustain heavy damage in the finale.

Maria and Jin frequently bicker, resembling an old married couple. Despite this, she consistently shows specific concern for his well-being in combat. Significant emotional moments include her tackle-hugging Jin while crying tears of joy after their final victory and escape from the enemy's exploding base. This dynamic is consistently teased as a potential romance, emphasized in both the finale and a post-series OVA sequel.

Her emotional responses sometimes trigger pivotal events: twice her tears fell onto the command console, inadvertently activating Bakuryu-oh for its first deployment and later re-energizing the three main mechs during a climactic battle. A recurring tendency is her focus on Jin during crises, sometimes overlooking pilots Asuka and Kouji when calling for assistance during Raijin-Oh's difficulties.