Mint Rubble, known as Mint Labule in the original Japanese continuity, is a 13-year-old girl abandoned by her parents before the series begins. Flashbacks suggest an affluent upbringing, showing her in elegant clothing, but her parents' constant absence due to busy schedules led to neglect and eventual abandonment. This experience fuels her early fixation on securing a boyfriend as a primary motivation.

After being left alone, she joins Stick Bernard and Ray's group. Initially viewed as an annoyance for her incessant talk of marriage and romance, Mint gradually earns acceptance within the team. Her companions develop protective instincts toward her despite her youthful and often impractical romantic pursuits. During the journey to Reflex Point, Mint displays resourcefulness and courage in multiple encounters, aiding the group's survival.

A critical episode strands the team on an island where locals betray Mars Base survivors to the Inbit. Mint's reliance on the group for protection becomes evident during this ordeal, which ends with their rescue by Houquet Emrose. Her character evolves from a singular focus on marriage to valuing her role within the team. Though she retains her spirited and occasionally frivolous demeanor, the journey fosters a deeper sense of belonging and purpose beyond her initial marital goals.

In the OVA "Love Live Alive," set after the main series, Mint appears among freedom fighters attending Yellow Belmont's concert. The OVA emphasizes concert footage and flashbacks without providing new character development or background for her.