Mayoi Hachikuji is a key character in the anime series Bakemonogatari. She is a young girl who carries a large backpack and is often seen wandering the streets due to her circumstances as a lost spirit. Her character is introduced when she encounters Koyomi Araragi, the protagonist, who helps her confront her unresolved issues from her past life. Mayoi's story deals with themes of loss, regret, and moving on. Despite her tragic background, she maintains a cheerful and lively demeanor, providing both comic relief and poignant moments throughout the series.