In a world forever changed by the emergence of Twinkle, a celestial power born from the light of the stars, humanity discovers the hidden potential within their souls. Each individual carries a Heart Core-a living essence that reflects their true nature, harboring the power to grow and flourish through faith, self-discovery, and connection. At the heart of this tale is Ryu Katsuya, a proud and fiery teenager wielding the raw might of explosive flames, and Mizu Shoga, a graceful healer with a gift for understanding the unspoken depths of the heart. Together with the spirited and resilient Hinata Neito and the steadfast and formidable Eito, they are thrust into an era of upheaval, where growth is forged through trials and they embark on a journey of growth, courage, and resilience to protect a world on the brink of change. As they navigate the tender moments of high school life and the intense clashes of an uncertain world, each of them must confront their fears, rise above their pasts, and discover the strength to protect what they hold dear. Along the way, they'll uncover the truth of their powers, the beauty of connection, and the light that can only be found by facing the darkest nights.