Miku Kobayakawa is a former S-Rank Keijo player who later transitions into the role of an instructor at the Setouchi Keijo Training School. In her capacity as a teacher, she specializes in delivering classroom lessons, contrasting with her colleague Hitomi Hokuto, who focuses on physical training. She is depicted as an adult woman with long, light-colored or green hair that reaches hip or past hip length. Miku first appears in the story at the age of thirty-three. Her background as a top-tier competitor informs her approach to instruction, and even after retiring from active competition, her skills remain sharp and undiminished. She is known for a distinctive verbal habit, frequently adding the word bomber to her remarks, such as in the expressions That's a letdown bomber or That's a troublesome bomber. Her personal specialty technique is the Demp Butt Roll, a move she used to overpower many opponents during her career. She also personally taught her signature maneuver, the Boob Dunk, to the character Kazane Aoba, indicating a direct mentorship relationship. In the manga, Miku serves as the sole accompanying instructor for the Elite Class during a training camp, while in the anime another instructor is also present. Her motivations appear rooted in guiding the next generation of Keijo athletes through theoretical and tactical knowledge, leveraging her own considerable experience as a former S-Rank player. Her development is largely defined by her shift from being an active competitor to a knowledgeable mentor, passing on her techniques and insights to younger characters within the story.