Harumi has brown skin and large medium-blue eyes. She has medium-length orange hair, which is usually tied back either in low pigtails or in a braid, and her bangs are messy, most of it covering her forehead in a triangular shape. A fang in the top right corner of her mouth sometimes appears.
Harumi's outfit consists of her school's uniform - a white collared shirt with a blue tie, a navy blue coat, and a black skirt with a thick navy blue stripe across the bottom of the skirt. Her everyday outfit often consists of a hoodie and jeans or a skirt.
Harumi's is hyper, energetic, weird, and annoying to some. She does not hesitate one bit when it comes to meeting people, except for Sakura Kyoto, the band's drummer. Harumi tends to get irritated by people who take everything too seriously, and also those who are more hyper than she is.
Contrary to her everyday personality, Harumi becomes very serious when it comes to playing her guitar.
Harumi plays rhythm guitar. Her guitar has a white body with a beige neck and head and silver tuning pegs. Her guitar strap is teal with white spots. She practices regularly and even gets Kazuki to practice with her sometimes.
Harumi often gets jealous and/or annoyed at Sakura, because they have the same outgoing and strange personalities, but Sakura is more popular than Harumi. Sakura, however, is quite oblivious about what Harumi thinks of her. When they first met, Harumi was reluctant to work with her and continuously held a grudge against her. However, as Harumi worked alongside Sakura more, she begins to realize that they have more than just a personality in common, and that they really get along well.