Chuuya Nakahara is a 22-year-old Port Mafia executive and one of its strongest combatants. He is short and slender but exceptionally athletic, with fair skin, vivid blue eyes, and short, messy reddish-orange hair. He wears a black fedora with a red band, a black button-up shirt, a black vest, fitted black pants, and black shoes, along with a long black coat draped over his shoulders, a choker, gloves, and various accessories. His style is elegant but practical, reflecting his position as a high-ranking Mafia member. Chuuya is passionate, confident, blunt, and quick-tempered. He has a strong sense of pride and dignity and hates being underestimated, especially because of his height. He is easily provoked and has a tendency to argue, particularly with Dazai, but he is not simply aggressive. Chuuya is loyal to people he trusts, takes his responsibilities seriously, and has a strong personal code. He can be surprisingly considerate beneath his rough exterior, though he rarely admits it. He enjoys fine clothing, wine, and expensive things, and has refined tastes despite his violent occupation. His ability, Upon the Tainted Sorrow, allows him to manipulate gravity. He can alter the gravitational force of objects and people he touches, making him extremely dangerous in close combat. He can also use gravity to move himself at incredible speeds and manipulate objects around him. His ultimate technique, Corruption, unleashes the full power of his ability but causes him to lose control, requiring Dazai’s ability to stop it. Chuuya’s relationship with Osamu Dazai is famously antagonistic. They were once partners in the Port Mafia and were known as Double Black. They constantly insult, provoke, and bicker with each other, yet possess extraordinary teamwork and an almost instinctive understanding of one another’s abilities. Chuuya deeply dislikes Dazai’s personality and schemes, but he recognizes Dazai’s intelligence and relies on their partnership when necessary. Despite their constant hostility, their history together makes their dynamic unusually complicated. As a Port Mafia executive, Chuuya commands respect and takes his position seriously. He is fiercely loyal to the organization and is willing to put himself in danger to complete a mission or protect those under his command. Beneath his fiery temper and sarcastic attitude, Chuuya is disciplined, dependable, and deeply devoted to the people and organization he considers his own.