Potamos, who adopts the human name Hiromi Kawanami, is a character in the anime Wedding Peach. She is a water demon from the demon world and the fourth major devil sent by Queen Raindevila to deal with the Love Angels, making her the third of the queen's subordinates to appear in the story. In the anime she debuts around episode twenty-nine, and in the manga she is introduced in the fourth volume. To operate in the human world, she disguises herself as Hiromi Kawanami, a middle school student at Sei Hanazono Gakuen whose human appearance is that of a teenage girl with pink eyes and short purple hair. Her original mission is to help the other devils, identify the Love Angels, and recover the sacred Saint Something Four items, but her focus quickly shifts once she becomes involved with the human world.

Potamos is a powerful combatant whose abilities are tied to water. She can manipulate ice and water, teleport across distances, and change her form to pass as human. When she transforms from her civilian appearance into her demon form, she goes through a two-step change that leaves her in a black leotard with metal protectors and a skirt, and her associated flower motif is the orange rose. As a fighter she is overconfident, viewing herself as superior to the Love Angels and expecting to defeat them easily.

As a person, Potamos is volatile and dramatic, acting on strong impulses and emotions. At first she is arrogant and condescending toward her enemies, but her personality takes a major turn when she meets Yousuke Fuuma and falls in love with him at first sight. Because Yousuke is a hybrid with both devil and human blood, she calls him V-kun and becomes openly devoted to him. Her infatuation makes her a rival to Momoko Hanasaki, who also loves Yousuke, and it distracts her from her duties as a demon. Her feelings are genuine but possessive, and when she learns that Yousuke loves Momoko instead of her, she loses control entirely. She reveals her true demon form, begins drawing the entire school into a black hole, and declares her intention to bring Yousuke back to the demon world so she can marry him.

Her role in the story is that of an antagonist who gradually becomes a sympathetic figure. She is sent to support the devil Igneous, but she ends up killing him after he grows soft under the Love Angels' influence. Later, her own experience with love causes her to repeat his fate. When her rampage endangers her own life, the Love Angels save her using the power of the Saint Something Four, and Wedding Peach's influence purifies her. She then renounces her demon identity, apologizes to Yousuke, and settles into ordinary life as Hiromi Kawanami.

Her development follows a clear redemption arc. By coming to know love, she finally understands what happened to Igneous and why he changed, and she lets go of her pride as a demon in order to live as a human. In the manga this resolution continues, as she later encounters a man who appears to be a reincarnation of Igneous, hinting at the possibility of a new relationship. In the anime's follow-up Wedding Peach DX, she goes further and returns as the fifth Love Angel, Angel Potamos, showing her full transformation from enemy to ally.

Within the story, her most important relationships are with Yousuke Fuuma, the object of her affection; Momoko Hanasaki, her rival who ultimately saves and befriends her through the power of the Love Angels; Igneous, the fellow demon whose fate foreshadows her own; and Queen Raindevila, her former master whom she abandons. Her water-based powers contrast with the Love Angels' abilities, and her emotional instability makes her both dangerous and vulnerable. Her arc illustrates the series' central idea that love can change even a demon and turn a determined enemy into one of the angels' own.