Sumiko Inoue

Sumiko Inoue is the childhood friend of protagonist Kota Shibaki, serving as the head of the school's disciplinary committee. Known for her strict adherence to school regulations, she frequently clashes with the carefree Shibaki, whom she considers a constant thorn in her side. Beneath her rigid exterior, however, lies a surprisingly passionate spirit — after accidentally purchasing the wrong instrument in middle school, she pushed herself relentlessly until she mastered the bass guitar, revealing a tenacious will to never give up. As the story unfolds, her feelings toward Shibaki gradually begin to shift in unexpected ways.