TV Special
Description
Klein, whose real name is Tsuboi Ryoutarou, is a major supporting character in the Sword Art Online franchise and appears in the Sword Art Online: Extra Edition special. He is a cheerful and hot‑blooded veteran gamer who became one of Kirito’s first friends during the death game of Sword Art Online. In the real world, he is an outgoing and loyal individual, always ready to lend a hand. His personality is marked by a lighthearted and comedic nature, often providing comic relief, but he is also a fiercely dependable warrior when the situation demands it.

In Sword Art Online: Extra Edition, Klein joins the group of protagonists in the virtual world of ALfheim Online as a member of the Salamander race. His primary role in the special is to participate in the Deep Sea Marauder quest, a mission undertaken to fulfill the wish of Yui, the AI daughter of Kirito and Asuna. Klein serves as a frontline fighter, using his katana‑based combat skills to support the party. He remains a loyal ally to Kirito, displaying unwavering commitment to protecting his friends. He also contributes to the group’s dynamic with his humorous attempts to flirt with the female characters, though these efforts are typically unsuccessful.

Klein’s motivations are rooted in his strong sense of loyalty and friendship. He values the bonds he formed during the traumatic SAO incident and is determined to support Kirito and the others in any way he can. He is the leader of the small but skilled guild Fuurinkazan, and he takes his responsibility to protect his guild members seriously. His relationship with Kirito is particularly significant; they share a deep trust despite Kirito’s initial guilt over leaving Klein at the start of the game. Klein never holds that against him and remains one of Kirito’s most reliable companions.

In terms of abilities, Klein is a proficient katana user. In SAO, he was one of the few players to obtain the unique Katana skill, making him a formidable fighter in close quarters. In ALfheim Online, he continues to employ a katana‑like weapon, and his combat prowess is respected among the front‑line players. While his character does not undergo major development in Extra Edition, his steadfast presence reinforces the theme of enduring friendships and the importance of the connections made during the death game.

Overall, Klein serves as a reliable big brother figure within the group. His blend of humor and combat skill, combined with his unwavering loyalty, makes him an integral part of the team in Extra Edition and throughout the series.