Leo Tsukinaga, a musical prodigy and eccentric former leader of idol unit Knights, channels his relentless creativity into crafting melodies that have resonated in his mind since childhood. Raised in a middle-class family, his early mimicry of TV idols to delight younger sister Ruka sparked a lifelong mission to spread joy through music. This innate genius fostered an unconventional adolescence, isolating him from typical social bonds while sharpening his artistic instincts. A whirlwind of chaotic energy and hidden sensitivity, Leo forgets names, scribbles lyrics on walls during inspiration surges, and depends on Knights members like Izumi Sena or Tsukasa Suou for daily structure. Yet beneath his disarray lies keen intuition and fierce loyalty, often casting himself as a self-sacrificing antagonist to shield others. His conflicts dissolve without resentment, replaced by unwavering affection that reveals layered emotional depths. At Yumenosaki Academy, Leo co-founded Knights (initially Chess) as leader until the "War" arc shattered his stability. Eichi Tenshouin weaponized Leo’s own DreamFes system against him, triggering a breakdown that led to school withdrawal and years of isolated composing. Wanderer Madara Mikejima intervened, guiding Leo through global travels that mended his psyche. He later rejoined Yumenosaki, ceding leadership to Tsukasa while remaining Knights’ creative heartbeat. Leo’s tangled bond with Eichi oscillates between rivalry and reluctant kinship, rooted in collaborative hospital music sessions that later curdled into betrayal. Though scarred by Eichi’s manipulations, he begrudgingly acknowledges their role in reforming Yumenosaki. His mentorship of Anzu showcases unexpected nurturing, entrusting her with compositional input and personal reliance. Within Knights, Tsukasa balances reverence for his genius with exasperation at his impulsivity, while Izumi and Ritsu anchor his chaos with pragmatic support. Globally celebrated compositions fund Knights’ prominence even during Leo’s absences. His magnetic stage presence thrives on improvisation, though spontaneous choreography changes test unit cohesion. Recurring motifs of "Toward the Unknown" mirror his quest to shape hopeful futures through music, fueled by Tsukasa’s faith and his evolving leadership. Pivotal arcs like Checkmate trace Leo’s collapse and rebirth, refining his creative ethos. Collaborations with Shu Itsuki and events like "King’s Horseback Ride" showcase healing through artistic synergy. Familial ties expose hidden tenderness: he shields sister Ruka from his disarray behind a crafted "cool" persona, while efforts to balance reciprocity with Madara underscore growth beyond past dependence. Leo’s journey weaves genius and fragility into a testament to music’s redemptive power, etching his legacy as Knights’ catalyst and the idol world’s mercurial heartbeat.