Popura Taneshima, also known as Poplar, is a main character in the anime Wagnaria!!. She is a seventeen-year-old high school student who works as a waitress at the family restaurant Wagnaria, where she is one of the more experienced members of the floor staff. She is extremely petite and has a very youthful appearance, and this is the defining trait of her character. Her parents named her after the poplar tree in the hope that she would grow tall, which is treated as an irony because she remains exceptionally small and is frequently mistaken for a much younger child, both by customers and by her co-workers.

In terms of personality, Popura is cheerful, bright, honest, and hardworking. She takes her job seriously and is dedicated to serving customers, although she is prone to occasional clumsy mistakes. She has a strong sense of responsibility and takes pride in being a senior staff member, and she consistently tries to behave as a proper senior toward the newer employees. Her decisions tend to be guided by what she thinks a senior should do rather than by her immediate emotions, and even when she feels anxious or discouraged she avoids abandoning her duties. At the same time, she is very sensitive about her small stature. Being treated like a child, or failing to be taken seriously because of how young she looks, visibly upsets her, though she usually manages to recover her spirits and return to her work.

Her main motivation is to be recognized and respected as a capable senior waitress despite her misleading appearance. She wants to prove herself to her colleagues and to fulfill her responsibilities properly, and she works hard to keep the atmosphere of the restaurant pleasant. Within the story, she functions as a stabilizing presence. She is present from the early part of the series as one of the more senior employees, and she helps to keep the workplace running smoothly while the many eccentric personalities around her create the comedy. She is also the one who guides and explains things to newcomers, doing her best to be helpful even when her small size undermines her authority.

Popura's most significant relationship is with Souta Takanashi, her junior at both the restaurant and their high school. She views him as her kouhai and expects to be treated as his senior, but he often fails to take her seriously because she looks like an elementary school student, which creates a recurring source of frustration and humor between them. A notable running gag is that she consistently mispronounces his surname as Katanashi instead of Takanashi. Among her other relationships, she maintains a considerate but somewhat careful working relationship with her co-worker Mahiru Inaba, and she relates to the store manager Kyouko Shirafuji as a diligent staff member under a manager who runs a very loose workplace.

Over the course of the anime, Popura develops emotionally and socially more than in any outward capability. Events that test her professionalism and expose her insecurities gradually help her build confidence in her own abilities, and she matures both as a worker and as a young adult, learning to cope with the way others perceive her. She has no supernatural or combat abilities; her notable strengths are her commitment to her job, her customer service skills, and her ability to keep the workplace atmosphere warm and stable.