Rio, orphaned in the capital slums of the Beltrum Kingdom, lost his father Zen shortly after birth to betrayal by the adventurer Lucius. His mother Ayame raised him alone until Lucius murdered her when Rio was five, traumatizing him and igniting a deep desire for revenge. Enslaved by a slum gang, he endured two harsh years. At age seven, Rio awakened memories of his previous life as Haruto Amakawa, a Japanese university student who perished in a bus accident. These memories merged with his own, granting Haruto's knowledge, skills, and emotional experiences while Rio retained his core identity. This fusion created a mentally mature individual possessing over two decades of lived experience despite his young body. His life shifted dramatically upon rescuing Princess Flora Beltrum from kidnappers, earning him enrollment in the Beltrum Royal Academy. There, he faced discrimination as a commoner but forged a close bond with his instructor, Celia Claire, who became his sole friend and confidante. After five years, false accusations of attempting to assassinate Flora during a military exercise forced him to flee the kingdom as a fugitive. Escaping, he encountered Latifa, a young fox beastkin assassin enslaved by Duke Huguenot. Rio defeated her and shattered her magical submission collar. Choosing freedom, Latifa accompanied him, eventually becoming his adoptive sister. Rio then traveled to the Forest of Spirits (Seirei no Tami), training in spirit arts and forming a spiritual contract with Aishia, a high-rank humanoid spirit. This period stabilized his abilities and helped reconcile his dual identity. Seeking his heritage, Rio journeyed to his mother's homeland, the Yagumo region. Meeting his grandparents and cousin revealed his royal lineage from the Karasuki Kingdom, providing context for his parents' past and solidifying his connection to the Far East. Returning to the Strahl region, he adopted the alias "Haruto Amakawa" to evade recognition as a wanted criminal. His return involved reuniting with figures like Celia, whom he rescued from a forced political marriage to Charles Arbor, demonstrating unwavering loyalty to those he cared for and marking a shift towards confronting his enemies. He later encountered Miharu Ayase, his childhood friend from his past life, who had been transported to the same world. Rio struggled with feelings for Miharu, believing his quest for vengeance rendered him unworthy of happiness, but gradually reconciled this conflict, acknowledging the importance of his bonds. Rio's development included interactions with other reincarnated individuals like Liselotte Cretia (who retained memories as Rikka Minamoto) and Satsuki Sumeragi, a summoned hero from Japan. These encounters forced him to confront his place in the world and responsibilities tied to his growing powers. His journey unveiled his original identity as the reincarnation of the Dragon King, a transcendent being tasked with protecting the world. This legacy granted him divine authorities like "Annihilation," enabling him to erase anything he fully perceives. Rio's perspective on relationships evolved; he accepted that his connections were sources of strength, influenced by his found family in the spirit village and his bond with Celia. Rio exhibits a reserved, pragmatic, and calm personality. He often maintains a neutral or stern expression to avoid attention, though his humility sometimes inadvertently incites envy in others like Hiroaki. His dual-life experiences make him exceptionally adaptable and strategic, approaching challenges with rationality. He initially downplayed his worthiness for happiness due to his vengeful motives, particularly concerning Miharu. However, interactions with close companions helped him value emotional bonds more deeply, shifting towards prioritizing these relationships. He displays fierce protectiveness when loved ones are threatened, occasionally responding mercilessly against aggressors. His relationship with Celia is particularly significant; he considers her his first true friend in this life and trusts her implicitly, even revealing his reincarnation secret. Rio possesses diverse abilities from both lives. From Haruto, he inherited proficiency in ancient martial arts, swordsmanship, and knowledge of languages (Japanese, Strahl, Yagumo, and Spirit tongues), engineering, farming, and cuisine. He further honed his swordsmanship at the Royal Academy, surpassing royal guards and developing a unique combat style. Spirit arts form his core magical abilities, enabling manipulation of all elements for healing, hypnosis, and crafting enchanted objects like hair-color-changing artifacts. His transcendent nature as the Dragon King reincarnation grants limitless mana and divine authorities. His contract with Aishia enables spirit assimilation, merging them into a single entity with enhanced capabilities like materializing "Spirit Arms." Additional skills include hunting, carpentry, noble etiquette, and medicine concoction. His equipment includes black wyvern leather armor, a destroyed mithril sword, a space-time cache for storage, and a portable rock house. Physically, Rio naturally has black hair, caramel eyes, a slender build, and scars from the slums. Using a spirit artifact for his alias "Haruto," he sported gray asymmetrical hair. After spirit assimilation with Aishia, his hair turned white, his eyes changed to crimson, and his scars vanished.