Menzi is a character who appears in the anime Pokémon Horizons: The Series. She is introduced as a Pokémon Trainer who has already achieved the rank of Master, a level of skill comparable to a Champion. Her first appearance takes place in the city of Cuencia, where she encounters the series' protagonists, Liko and Roy, while they are searching for information about the Legendary Pokémon known as the Black Rayquaza.

In terms of personality, Menzi is portrayed as being full of enthusiasm and energy. She is a passionate Pokémon battle lover whose excitement for training and combat is a defining trait. Despite her high rank and proven strength as a Trainer, she is not aloof or distant. Instead, she readily involves herself with others, offering her assistance to Liko and Roy without hesitation.

Menzi's primary role in the story is that of a supportive mentor and a powerful ally to the main characters. When Liko and Roy seek out the Gym Leader Brassius, they meet Menzi first. Finding Brassius in a state of deep melancholy, she takes the initiative to help the young Trainers gather a group of Helioptile Pokémon to cheer him up and inspire him to battle again. Later, she directly takes on a mentoring role, such as when she proposes an intense training regimen for Roy and his Pokémon Fuecoco to help them improve their speed and power following a difficult defeat. Her motivation stems from a clear love for the art of Pokémon battling, and she seems driven to help others grow stronger as Trainers. She is recognized as a Champion-level Trainer right from her debut.

Regarding key relationships, Menzi quickly establishes a positive and helpful rapport with the protagonists, Liko and Roy. She acts as a friendly figure who supports their journey rather than serving as a rival. Her background, including details about her family or her life before becoming a Master Rank Trainer, is not explored within the episodes described in the source material.

As her role in the narrative progresses, Menzi shows development by transitioning from a powerful stranger who offers temporary help to a dedicated mentor who takes a personal interest in the growth of a specific Trainer like Roy. This demonstrates a commitment to nurturing the potential of others. Her notable abilities are clearly defined; she is a Trainer of the highest caliber, having reached Master Rank, which sets her apart from ordinary Trainers and establishes her as a formidable and knowledgeable battler.