Miyu Yamazaki is a main character in the anime Super GALS! and the best friend of the protagonist Ran Kotobuki. At the start of the series, she is a sixteen-year-old high school student with short blonde hair and a cheerful, sweet demeanor. However, her outward kindness masks a troubled past. When she was in elementary school, her parents divorced, and she lived with a mother who was distant and more focused on finding a new partner than on caring for her. Feeling abandoned and angry, Miyu became the leader of a street gang called the Resistance, and she developed a rough, threatening personality that instilled fear in others. Her life changed when she encountered Yamato Kotobuki, Ran’s older brother, who was then a rookie police officer. Yamato saved her from a dangerous situation and, through his persistent kindness and encouragement, inspired her to abandon her delinquent ways. She fell deeply in love with him and resolved to become a good person, a decision that led her to reform her behavior and eventually become close friends with Ran.

In her new life, Miyu presents herself as a bubbly, affectionate, and polite girl who often refers to herself in the third person as a cutesy mannerism. She is fiercely loyal to her friends, particularly Ran and Aya Hoshino, and is always willing to help them with their problems. Despite her gentle exterior, she retains the fighting instincts and physical prowess from her gang days; when provoked or when someone she cares about is threatened, she can revert to a fierce and intimidating demeanor. She is also an artistic person who enjoys drawing and painting, using art as a way to express herself and cope with past hardships.

Her motivation is primarily driven by her love for Yamato and her desire to live up to his expectations. She strives to be a good friend and a responsible citizen, though she still enjoys the gal lifestyle, including fashion and hanging out in Shibuya. Her relationship with Ran is central to the story: the two share a deep bond, and Ran often teases her about her romantic feelings for Yamato. Miyu’s relationship with Yamato is a recurring subplot, characterized by mutual affection and frequent comedic interruptions when they attempt to share a kiss.

Throughout the series, Miyu undergoes significant development from a former delinquent into a more mature and caring individual, though she never fully loses her edge. Her journey involves confronting her past, reconciling with her mother, and finding her place in the Kotobuki family after she marries Yamato in the sequel storyline. Notable abilities include her exceptional fighting skills, which make her a capable defender of her friends, and her artistic talent, which is recognized and praised by others. She plays a key role as a loyal friend and emotional anchor within the main trio, providing support and occasional comic relief.