Coconna Vartla first appears as a young orphan navigating the harsh streets of Uoodo City, a setting defined by crime and corruption. Despite these challenging circumstances, she retains a certain resilience and manages to hold onto her innocence. Initially, she is portrayed as brash, argumentative, and highly profit-driven, often inserting herself into situations to find some financial gain while complaining about the risks involved. She is part of a small group of scavengers and misfits that includes the experienced salvager Gotho and the former pilot Vanilla Vartla, with whom she shares a contentious relationship.

This belligerent sexual tension with Vanilla is a hallmark of her early dynamic, marked by constant arguing and loud confrontations which test the patience of those around her. However, this relationship evolves significantly over time, eventually culminating in marriage and the raising of six children together. Despite her frequent complaints, Coconna proves her value through her actions. She is a highly capable driver, able to maintain her composure and operate various vehicles skillfully even under the duress of heavy combat. This skill makes her an indispensable asset during high-risk escapes and clashes with military forces.

Her role within the group is deeply intertwined with the protagonist Chirico Cuvie. Upon meeting him, she develops a searing crush that often overrides her self-interest, pushing her reluctant companions to offer Chirico assistance when he is in trouble. This creates a love triangle dynamic, as she finds herself competing with the enigmatic Fyana for Chirico's affections. Over the course of time, her initial suspicion and hostility towards Chirico transforms into a deep loyalty, and she becomes part of his found family, providing him vital emotional grounding and practical support.

The Phantom Arc revisits Coconna decades after the original adventures. Now married to Vanilla, their relationship has experienced a long and rocky period with significant ups and downs. For their silver anniversary, Vanilla, with the help of their old friend Gotho, arranges a special trip as a gesture to make amends and improve their strained marriage. She returns with them to the familiar setting of Uoodo, a journey intended to be a trip down memory lane to reflect on the hardships and adventures of their past. However, this journey is also driven by a lingering hope to reunite with the elusive Chirico. Upon arriving at the Uoodo Battling arena, the group encounters a mysterious red-shouldered Armored Trooper, and Coconna finds herself drawn into an ancient prophecy concerning Chirico's legacy. Throughout this OVA, her recollections and interactions highlight the enduring bonds she shares with her former comrades, and her narrative ultimately concludes with her established family life, signifying her transition away from the high-risk escapades of her youth.