Kirigaya Kazuto

Kirigaya Kazuto, better known by his in-game name Kirito, is the main protagonist of the Sword Art Online anime.

He's a tall, slim, black-haired teenage boy (around 14–17 years old across the different arcs) with dark eyes that often appear serious or intense. In the virtual worlds, his default avatar usually features black clothing — most iconically the long black coat (the "Blackwyrm Coat" later on) — which, combined with his black hair and dual-wielding skill, earns him the title "The Black Swordsman".

Personality-wise in the anime:

• Extremely skilled and resourceful gamer
• Calm and composed under pressure, often appearing cold or aloof at first
• Actually deeply caring, especially toward those he gets close to (though he rarely shows it openly)
• Carries a strong sense of responsibility and guilt (particularly after the early SAO deaths)
• Prefers to act alone rather than rely on others (the "solo player" mindset), though he gradually opens up and forms important bonds
• Very protective of his friends and loved ones, sometimes to a self-sacrificing degree

In the Aincrad arc he's portrayed as a legendary solo player who becomes famous (and somewhat feared) for clearing floors ahead of most groups and for his unheard-of Dual Blades unique skill. As the story progresses through later seasons (Alfheim, Gun Gale, Alicization, etc.), he matures further while still retaining his core traits: quiet confidence, exceptional combat ability, and a reluctance to let others get too close emotionally.