Ryōhei Arisu (also romanized as Ryohei Arisu) hails from a prestigious family; his father served as an education department superintendent. His mother's death during his childhood fostered strained dynamics, marked by constant comparisons to his academically successful younger brother, Hajime, and frequent paternal criticism that eroded his self-worth. During elementary school, Arisu befriended Daikichi Karube after Karube defended him from bullies. This bond endured into high school when he met Chōta Segawa, initially perceived by Arisu as "idiotic and hopeless" but later earning his respect through kindness. The trio became inseparable, frequently spending time together despite their youth, often at Karube's bar. Some adaptations depict Arisu as a NEET prior to entering the Borderlands, having dropped out of university, becoming engrossed in video games, and clashing with his family over his directionless life. Arisu's life irrevocably changed when transported with his friends to the Borderland, a parallel Tokyo where survival hinges on winning dangerous games. Initially naive and overwhelmed by the lethal stakes, he witnessed death firsthand during early games like "Dead or Alive" (Three of Clubs) and "Tag" (Five of Spades), forcing him to confront the Borderland's brutality. His observational skills and analytical mind, honed through video games, became crucial assets. He demonstrated an ability to map environments, deduce game rules, and identify patterns, particularly in logic and puzzle games, initially aligning him with Diamonds (♦️). A defining trauma occurred during the "Hide and Seek" game (Seven of Hearts), a Hearts (♥️) game designed to provoke betrayal. Forced into a scenario requiring a single survivor, Arisu witnessed the sacrificial deaths of Karube, Chōta, and Shibuki, who ensured his survival. This plunged him into profound despair and guilt, fundamentally altering his psyche. Following this, he partnered with Yuzuha Usagi, a skilled mountain climber. Their alliance evolved into deep mutual reliance and eventual romance; Usagi's resilience provided stability, while Arisu's strategic mind navigated their challenges. The Seven of Hearts experience, coupled with later confrontations—particularly criticism from Suguru Niragi and insights from Ginji Kyuma (the King of Clubs)—forced Arisu to recognize his inherent selfishness. He realized actions like initially pairing Usagi with her assailant stemmed from deep-seated insecurities and emotional neglect. This catalyzed significant growth. He consciously worked to prioritize others' needs, exemplified during the Ten of Hearts ("Witch Hunt") game at the Beach, where he exposed manipulative rules to save players. His specialty solidified as Hearts (♥️) due to his developing understanding of psychological manipulation and emotional cores. Arisu faced the Queen of Hearts game (Croquet) in the final stage, involving intense psychological warfare leveraging hallucinations of his deceased friends to break his spirit and tempt forfeit. Despite severe turmoil, he persevered, rejecting the Queen's nihilism and affirming his commitment to life and his promise. Surviving the Borderland and returning, Arisu emerged with renewed purpose: to live meaningfully, honor his friends' sacrifices by pursuing education and a career, and cherish connections, particularly with Usagi. In the sequel manga "Alice in Borderland: Retry," set years later, Arisu and Usagi are married and expecting their first child. Physically, Arisu is a tall, lanky young man with messy, shaggy black hair (sometimes described with a blue tint) and pale skin. He wears casual clothing like t-shirts, hoodies, and jeans. His personality evolved from an insecure, sometimes selfish individual burdened by familial neglect and academic failure into a resilient leader defined by loyalty, strategic intelligence, and a hard-won sense of responsibility. His Borderlands journey forced him to confront deepest flaws and traumas, forging a stronger, more compassionate individual determined to value life and human connection.