Living a contented solitary existence, a young woman delves into mastering Chanting Skills, a unique art enabling one to materialize and summon their 'heart.' In her pursuit to bridge the gap with someone special, she immerses herself in the colors of Keinez (red), Ruguz (blue), Surisuz (yellow), Beorc (green), and Arzus (white), each requiring a specific catalyst to evoke through melodic incantations. Enrolled in a vocational school where these enigmatic abilities are honed, Kluele encounters Neight, a transfer student wielding unconventional Night Colour chants that captivate her curiosity. Meanwhile, the renowned Rainbow User, Xins, hunts for a practitioner of Night Colour skills, setting a stage for unexpected alliances and rivalries.