Marta, known in her civilian identity as a fourteen-year-old schoolgirl, is the present‑day incarnation of Sailor Venus, the guardian of love and beauty. She was the first of the inner guardians to awaken her powers, activated by the white cat Artemis when she was thirteen, and she operated alone for nearly a year under the alias Sailor V before joining the other Sailor Guardians. Her solo career involved fighting agents of the Dark Kingdom in Japan and later in London, where she formed a close friendship with an Interpol officer named Katarina and fell in love with a young man named Allan. When she saw that Katarina and Allan had fallen for each other, she quietly left England, allowing them to believe she had died in an explosion, and returned to Japan. This early experience gave her a seasoned, mission-focused demeanor when she first met Sailor Moon and the other guardians, but as the series progresses her lighter, more playful and sometimes scatterbrained personality emerges, especially in her enthusiasm for pop idols, romance, and volleyball.

Marta’s core motivation is her unwavering sense of duty to protect the moon princess and her team. She takes her role as the leader of the four inner guardians seriously, often providing strategic guidance and steadying the group during crises. In SuperS, her commitment is tested as the Dead Moon Circus targets the dreams of children and the guardians themselves. She is fiercely loyal, self‑sacrificing, and willing to risk her life for her friends, yet she also embraces a cheerful, sometimes boy‑crazy side that leads her into comedic situations, such as briefly dating two villains who are members of the Amazon Trio.

Within the story of SuperS, Marta serves as a reliable frontline fighter alongside Usagi (Sailor Moon), Ami, Rei, and Makoto. She is particularly close to Usagi, sharing a friendship built on mutual support and a shared sense of humor; she also acts as a protective older‑sister figure to Chibiusa. Her relationship with Artemis is that of a trusted partner and confidant. As a member of the team, she contributes her combat experience and her ability to inspire those around her, often acting as the one who rallies the others when morale is low.

Over the course of the series, Marta undergoes noticeable development. In her earliest appearances she is disciplined and almost stern, carrying the weight of her solo battles. As she bonds with the other guardians, she gradually allows her more carefree and adventurous nature to surface, becoming more open about her dreams of becoming a singer or idol. In SuperS she obtains the ability to transform into Super Sailor Venus using the Venus Crystal Power, which marks a significant increase in her power and reflects her growing inner strength and maturity. Despite her occasional flakiness in everyday life, she consistently rises to the occasion when lives are at stake.

As Sailor Venus, Marta commands powers tied to light, love, and metal. Her signature attack is the Crescent Beam, a concentrated laser fired from her index finger. She later develops the more powerful Crescent Beam Shower, which releases a spread of light projectiles. Her most iconic weapon is the Venus Love‑Me Chain, a golden chain formed of heart‑shaped links that can entangle enemies, restrain them, or deliver damage. With the Super Sailor upgrade she gains the Venus Love and Beauty Shock, a heart‑shaped energy blast that embodies her domain of love and beauty. She also possesses superhuman strength and agility, able to wield heavy weapons with ease and make enormous leaps, and she is highly skilled in hand‑to‑hand combat, having trained during her time as a solo vigilante. Her physical prowess is often underestimated due to her slight build, but she is one of the strongest members of the team.