Fifteen-year-old Miyagami Private Academy student Ayumu Oume, nicknamed Ayu-Ayu or Ayu-Chan, serves on the Best Student Council's Covert Squad. Born September 15 with brown hair and hazel eyes, she hails from the Oume ninja clan but left its restrictive traditions, especially those limiting her personal expression and clothing choices. She shares a close bond with Rino Rando, whom she introduced to the council, and has a twin brother named Utaro Ohme.

Ayumu utilizes her potential ninja skills for intelligence gathering and covert operations within the squad. Her rejection of clan expectations deepened when scouted as an idol under the stage name AYU-AYU; initial enthusiasm turned to refusal upon learning her management planned a ninja-themed image and outfit, directly opposing her reasons for leaving the clan. This choice underscores her consistent prioritization of personal autonomy.

Initially an unnamed background character, Ayumu gained narrative focus, particularly during her idol career exploration episode. She remains an active Covert Squad operative and a supportive presence in the student council.