Peko Pekoyama is the reserved Ultimate Swordswoman. She is fairly quiet and reserved, often not choosing to interject in her classmates' shenanigans. She's incredibly calm, poker-faced and logical, rarely showing her true emotions. Around Fuyuhiko, and later Hajime, true parts of her personality and personal life begin to slip through the cracks, such as her love of animals. She once forgot how to smile, and is trying to learn how to express herself, and make her friends happy.

Peko has the lowest female voice, with quite a serious, quiet tone.