Mayuka is the adopted daughter of Vidaux Völker, a former police inspector turned mercenary. Vidaux killed her biological father in revenge for the hit-and-run accident that caused his wife's death, subsequently adopting Mayuka. The two forged a close familial bond and travel constantly together.

She is typically present alongside Vidaux in their custom vehicle, equipped with an AI navigator named Graham. Mayuka possesses a quiet demeanor and often reads books during moments of respite. Throughout their travels, she remains a supportive presence in Vidaux's life, reflecting a relationship built on mutual dependence and care despite its violent inception.

Within the narrative, Mayuka becomes involved in aiding Derrida Yvain after his awakening from a decade-long cryogenic sleep. Alongside Vidaux and Graham, she joins Derrida's quest to locate Mage Bilstein and address a critical flaw in autonomous machines that has triggered global conflict. Her role within the group is primarily supportive.

Her backstory, including the circumstances of her adoption and the impact of Vidaux's actions, unfolds through interactions and flashbacks. The story concludes with her continuing to travel with Vidaux, maintaining their established dynamic.