Moe Mizukoshi attends Kazami Academy's senior high division, specifically Class 1-2, placing her one grade above Junichi Asakura. Her surname combines the kanji for "water" (水) and "surpass" (越), while her given name "Moe" (萌) means "bud" or "sprout". She stands 159 cm tall, weighs 41 kg, and has measurements of 87-57-86 cm. Her teal hair is typically styled in a waist-length ponytail with spiky bangs, complementing her gentle blue "tareme" eyes. She is often depicted wearing a sailor school uniform, thigh-high stockings, or a maid dress. Gentle, polite, and notably absentminded, Moe speaks slowly with a carefree, docile demeanor. She chronically relies on sleeping pills, leading her to fall asleep spontaneously, even while walking. This medication stems from her use of the magical sakura tree's power to dream of a boy she loved, who died in a traffic accident years prior. She carries a small xylophone, though not driven by musical ambition, and possesses exceptional knowledge of "nabe" (Japanese hot pot dishes), frequently discussing them at length. She often cooks and eats nabe on the school rooftop with her younger sister, Mako Mizukoshi. Despite her refined "Yamato Nadeshiko" demeanor, she exhibits naivete and poor judgment, such as attempting to pet venomous octopuses or consuming hallucinogenic mushrooms despite warnings. Unaware of her physical attractiveness, her unintentional physical closeness with others causes discomfort among female peers. Moe lives with her sister Mako and younger brother Tomoya Mizukoshi, a soccer player. After graduating high school, she works part-time at Kazami Academy and performs as a street musician with her xylophone and a trained monkey.