Benten is an alien from the Fukujin clan, also known as the Gods of Luck, and she is a childhood friend of the series' female protagonist, Lum. Her creation was inspired by the Japanese Buddhist goddess Benzaiten, but unlike that elegant and artistic figure, Benten was given a deliberately tomboyish and violent persona. She first appears when Lum returns to her home planet with her fiancé, Ataru Moroboshi, to participate in an annual traditional battle between their clans. Despite finding Ataru annoying, Benten briefly pretends to return his affections to anger Lum, which causes Lum's clan to lose the competition.

Benten has a rough, rowdy, and headstrong personality, often described as a space biker chick. She is frequently seen wearing a chainmail bikini, swearing, and reveling in fights, which she treats like a full-scale war using a high-tech bazooka and explosives. Her mood usually alternates between being laid back and violently aggressive, and she has a very short fuse. However, beneath this tough exterior, she possesses a surprisingly cute face and is a sassy, smart, and easy-going individual with a strong sense of honor and humor. Despite her masculine personality, she is perfectly capable of understanding the appeal of being a woman. She also has a noted love for gambling, a trait linked to her origin as a goddess of luck.

Benten is a fiercely loyal friend, particularly to Lum, and is always willing to help her when she is in trouble. Their friendship dates back to their early school years, where they, along with their other classmates Ran and Oyuki, had a habit of causing mischief, which often resulted in Ran getting hurt or blamed. While she is close to Lum, Benten does not trust Ran, keeping a sharp eye on her schemes. Benten also develops a notable relationship with the character Ryunosuke Fujinami. After a rough start, they become close friends and are frequently seen together, supporting one another in various challenges and competitions.

Over the course of the series, Benten is involved in many unusual situations, from challenging middle-school space girls to retrieve her motorcycle's ignition key to helping a friend find a lost kitten, which results in a high-speed chase with a biker gang. She is so fond of Earth that she visits frequently, even outside of the annual Setsubun festival when her clan traditionally battles Lum's Oni clan.

Her most prized possession is her flying airbike, which she maintains herself, and a chain she always wears like a sash. This chain serves a surprisingly mundane yet crucial function as the key to her house, and she was once locked out for ten days after it was stolen and accidentally destroyed. Her other notable abilities include piloting her airbike, impressive physical strength, and proficiency with a variety of futuristic weapons.